Support for overlaps json operator

Suggestion

The connector support the "contains" json/array operator. This operator select rows which contain ALL value in the array.
I propose the support the "overlaps" json/array operator. This operator select rown which contain ANY value in the array.

Use Cases

With this feature, you will be able to use the JSON Array [array operator &&] operator from PostgreSQL(https://www.postgresql.org/docs/current/functions-array.html).

Examples

Row 1: [ A, B]
Row 2: [C, D]
Row 3: [E, A, B ]
Look for any row which overlaps with [C, F] => Should return Row 2

Acceptance criteria

• Doc
• Test
• Code

It is very easy to implement. Unfortunately, I don't know how to use correctly GitHub for PR. So, I can provide code, and i hope someone will be able to PR it.

/test/postgresql.test.js line 294 -------------

 it('should support the "overlaps" where filter for array type field', async () => {
    await Post.create({
      title: 'Overlaps: LoopBack Participates in Hacktoberfest',
      categories: ['OL_LoopBack', 'OL_Announcements'],
    });
    await Post.create({
      title: 'Overlaps: Growing LoopBack Community',
      categories: ['OL_LoopBack', 'OL_Community'],
    });

    const found = await Post.find({where: {and: [
      {
        categories: {'overlaps': ['OL_Super', 'OL_Community']},
      },
    ]}});
    found.map(p => p.title).should.deepEqual(['Overlaps: Growing LoopBack Community']);
  });

/lib/postgresql.js, line 553 ------------------------------------------------------

case 'overlaps':
  return new ParameterizedSQL(columnName + ' && array[' + operatorValue.map(() => '?') + ']::'
    + propertyDefinition.postgresql.dataType,
  operatorValue);
case 'contains':
  return new ParameterizedSQL(columnName + ' @> array[' + operatorValue.map(() => '?') + ']::'
    + propertyDefin

README.md line 601---------------------------------------------------

Operator overlaps
The overlaps operator allow you to query array properties and pick only
rows where the stored value contains any of the items specified by the query.
The operator is implemented using PostgreSQL array operator &&.
Note The fields you are querying must be setup to use the postgresql array data type - see Defining models above.

Comienza con el manejo existente de operadores de arrays cerca de la línea 553 de lib/postgresql.js y los casos relacionados en test/postgresql.test.js. Añade cobertura para las intersecciones en las que filter usa el ejemplo del issue y, después, actualiza la documentación de operadores alrededor de la línea 601 de README.md. Se considera terminado cuando el test pasa y el comportamiento de intersección de arrays de PostgreSQL está documentado.