Refs not resolved in components when paths are not present

Originally flagged here: https://github.com/swagger-api/swagger-parser/issues/664#issuecomment-479464930
References in components are only resolved when the paths object is present with referenced schemas. References should resolve for components when just the components object is present.

So when I have:

val yaml = "openapi: 3.0.0\n" +
  "info:\n" +
  "  version: 0.0.0\n" +
  "  title: Simple API\n" +
  "components:\n" +
  "  schemas:\n" +
  "    Product:\n" +
  "      properties:\n" +
  "        product_id:\n" +
  "          type: string\n" +
  "          description: >-\n" +
  "            Unique identifier representing a specific product for a given\n" +
  "            latitude & longitude. For example, uberX in San Francisco will have\n" +
  "            a different product_id than uberX in Los Angeles.\n" +
  "    Bag:\n" +
  "      type: array\n" +
  "      items:\n" +
  "        $ref: '#/components/schemas/Product'";

val parser = new OpenAPIV3Parser
val options = new ParseOptions
options.setResolveFully(true)
val openAPI = parser.readContents(yaml, null, options).getOpenAPI
println(openAPI.getComponents.getSchemas.get("Bag").toString)

The references are never resolved, the output of the Bag Schema is:

class ArraySchema {
    class Schema {
    type: array
    format: null
    $ref: null
    description: null
    title: null
    multipleOf: null
    maximum: null
    exclusiveMaximum: null
    minimum: null
    exclusiveMinimum: null
    maxLength: null
    minLength: null
    pattern: null
    maxItems: null
    minItems: null
    uniqueItems: null
    maxProperties: null
    minProperties: null
    required: null
    not: null
    properties: null
    additionalProperties: null
    nullable: null
    readOnly: null
    writeOnly: null
    example: null
    externalDocs: null
    deprecated: null
    discriminator: null
    xml: null
}
items: class Schema {
    type: null
    format: null
    $ref: #/components/schemas/Product
    description: null
    title: null
    multipleOf: null
    maximum: null
    exclusiveMaximum: null
    minimum: null
    exclusiveMinimum: null
    maxLength: null
    minLength: null
    pattern: null
    maxItems: null
    minItems: null
    uniqueItems: null
    maxProperties: null
    minProperties: null
    required: null
    not: null
    properties: null
    additionalProperties: null
    nullable: null
    readOnly: null
    writeOnly: null
    example: null
    externalDocs: null
    deprecated: null
    discriminator: null
    xml: null
}

}

However when paths are included, referring the schemas, it does resolve the references, so when I have:

    val yaml = "openapi: 3.0.0\n" +
"info:\n" +
"  version: 0.0.0\n" +
"  title: Simple API\n" +
"paths:\n" +
"  /:\n" +
"    get:\n" +
"      responses:\n" +
"        '200':\n" +
"          description: OK\n" +
"          content:\n" +
"            '*/*':\n" +
"              schema:\n" +
"                $ref: '#/components/schemas/Bag'\n" +
"components:\n" +
"  schemas:\n" +
"    Product:\n" +
"      properties:\n" +
"        product_id:\n" +
"          type: string\n" +
"          description: >-\n" +
"            Unique identifier representing a specific product for a given\n" +
"            latitude & longitude. For example, uberX in San Francisco will have\n" +
"            a different product_id than uberX in Los Angeles.\n" +
"    Bag:\n" +
"      type: array\n" +
"      items:\n" +
"        $ref: '#/components/schemas/Product'";

The output is:

class ArraySchema {
    class Schema {
    type: array
    format: null
    $ref: null
    description: null
    title: null
    multipleOf: null
    maximum: null
    exclusiveMaximum: null
    minimum: null
    exclusiveMinimum: null
    maxLength: null
    minLength: null
    pattern: null
    maxItems: null
    minItems: null
    uniqueItems: null
    maxProperties: null
    minProperties: null
    required: null
    not: null
    properties: null
    additionalProperties: null
    nullable: null
    readOnly: null
    writeOnly: null
    example: null
    externalDocs: null
    deprecated: null
    discriminator: null
    xml: null
}
items: class Schema {
    type: null
    format: null
    $ref: null
    description: null
    title: null
    multipleOf: null
    maximum: null
    exclusiveMaximum: null
    minimum: null
    exclusiveMinimum: null
    maxLength: null
    minLength: null
    pattern: null
    maxItems: null
    minItems: null
    uniqueItems: null
    maxProperties: null
    minProperties: null
    required: null
    not: null
    properties: {product_id=class StringSchema {
        class Schema {
            type: string
            format: null
            $ref: null
            description: Unique identifier representing a specific product for a given latitude & longitude. For example, uberX in San Francisco will have a different product_id than uberX in Los Angeles.
            title: null
            multipleOf: null
            maximum: null
            exclusiveMaximum: null
            minimum: null
            exclusiveMinimum: null
            maxLength: null
            minLength: null
            pattern: null
            maxItems: null
            minItems: null
            uniqueItems: null
            maxProperties: null
            minProperties: null
            required: null
            not: null
            properties: null
            additionalProperties: null
            nullable: null
            readOnly: null
            writeOnly: null
            example: null
            externalDocs: null
            deprecated: null
            discriminator: null
            xml: null
        }
    }}
    additionalProperties: null
    nullable: null
    readOnly: null
    writeOnly: null
    example: null
    externalDocs: null
    deprecated: null
    discriminator: null
    xml: null
}

}

Start with the OpenAPIV3Parser and ParseOptions usage shown in the report, then trace how setResolveFully(true) processes schemas under components when paths is absent. Reproduce both YAML cases and make the components-only case resolve the Bag items reference consistently with the paths case.