Update ilike operator and default operator for mongo filters

[michael-dean-haynie]

❗These are breaking changes and should probably be coordinated with the frontend team.

1. Update ilike to $like
The MongoDB-Style filtering logic supports a custom operator we've been calling ilike. We want to change this to $like to be more consistent with the other mongo operators (which all start with "$").

Example:

• Previous Format: filter[name][ilike]=brad --> { LIKE: [ '#name', '%brad%' ] }
• New Format: filter[name][$like]=brad --> { LIKE: [ '#name', '%brad%' ] }

2. Update default operator behavior for strings
Currently, if the filter parameter in the querystring omits the operator part for a string value, it will default to ilike.
We want to change this to strict equality ($eq)

Example:

• Previous Functionality: filter[name]=brad --> { LIKE: [ '#name', '%brad%' ] }
• New Functionality: filter[name]=brad --> { '=': [ '#name', 'brad' ] }

Also In-scope

• Updating unit tests and descriptions
• updating readme descriptions and examples

[roy-coder]

Moved to https://bitovi.atlassian.net/browse/HATCH-541.