Add validations for parameters map in Link class

[amit1307]

Description of issue

A map of key-value, called parameters, can be provided while creating a Link object. Currently there are no validations for the input parameters. Add the below validations for the parameters:

• If the key contains a ., then the first part should be one of the valid locations https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.1.0.md#parameterIn

• The value should be a constant or an expression. An expression starts with $ and needs to conform to what is defined in the link above. So for example, it should be one of : $url" / "$method" / "$statusCode" / "$request." source / "$response." source