[aspnetcore] string enums are invalid

Description

C# auto generated aspnetcore project contains invalid enums

Swagger-codegen version

2.3.1

Swagger declaration file content or url

Gist here

yaml code

  status:
	type: "string"
	description: "pet status in the store"
	enum:
	- "available"
	- "pending"
	- "sold"

Command line used for generation

editor.swagger.io

Steps to reproduce

1. Take code from gist
2. Paste into editor.swagger.io (http, not https)
3. Generate an aspnetcore server
4. Model generated looks like the following:

        public enum StatusEnum
        { 
            /// <summary>
            /// Enum AvailableEnum for available
            /// </summary>
            [EnumMember(Value = available)]
            AvailableEnum = 1,
            
            /// <summary>
            /// Enum PendingEnum for pending
            /// </summary>
            [EnumMember(Value = pending)]
            PendingEnum = 2,
            
            /// <summary>
            /// Enum SoldEnum for sold
            /// </summary>
            [EnumMember(Value = sold)]
            SoldEnum = 3
        }

This is invalid C#, the Value = x should be Value = "x".

Related issues/PRs

Possibly related

Suggest a fix/enhancement

Generated model should look like the following:

    public enum StatusEnum
    { 
        /// <summary>
        /// Enum AvailableEnum for available
        /// </summary>
        [EnumMember(Value = "available")]
        AvailableEnum = 1,
        
        /// <summary>
        /// Enum PendingEnum for pending
        /// </summary>
        [EnumMember(Value = "pending")]
        PendingEnum = 2,
        
        /// <summary>
        /// Enum SoldEnum for sold
        /// </summary>
        [EnumMember(Value = "sold")]
        SoldEnum = 3
    }

Reproduce the issue with the linked Swagger declaration or gist in editor.swagger.io and generate the aspnetcore server. Start by locating the template or generator path that emits the shown StatusEnum and EnumMember attributes. Done means the generated C# uses quoted enum values and the model is valid C#.