[FEATURE][Spec Linter] Enforce string or string[] for comma-seperated path params

[nhtruong]

Many OpenSearch path params accept an array of values in the form of comma-separated list of values. This can be represented as a string or an array:

schema:
  anyOf:
    - type: string
    - type: array
       items:
         type: string

However, many of of such path params in our spec are described as one of the two, but not both. To enforce this, we should look for 1 of the following:

• If a path param is described as an array only, it should throw an error because that path param will also accept a comma-separated string equivalence.
• If the description of the path param mentions comma separated or comma deliminated (with or without hyphen), we must also enforce string | string[] schema.