[REFACTOR] Refactoring Identifier Parsing in JSqlParserCC.jjt for Consistency #2214

Hi,

To improve the consistency of the codebase, I propose standardizing the parsing of identifiers in JSqlParserCC.jjt. Currently, there are multiple methods used to parse identifiers, including direct usage of S_IDENTIFIER, using RelObjectName(), and allowing various options with OR conditions. This inconsistency can lead to maintenance challenges and potential parsing errors.

By unifying the parsing method to consistently use a single approach, whether it is RelObjectName() or another method, we can achieve the following benefits:

1. Improved Code Readability: A single, consistent method for parsing identifiers will make the code easier to read and understand.
2. Reduced Maintenance Effort: With a unified approach, future changes to identifier parsing will only need to be made in one place.

I recommend refactoring all instances where identifiers are parsed to use a single, consistent method. This change will streamline the code and improve overall code quality.

I would appreciate your feedback on this proposal and any additional suggestions you might have.