[FEATURE] Allow regex flags

[rhazn]

User Story

1. As a {user}
2. I want {to use regex flags}
3. So that {I can use the full power of regex}

User Acceptance Criteria

• Regex flags g, m and i can be used in Jayvee

Examples

• consider the following transform: 'Hello Test Test' replace /Test/ with 'World, before this it returns 'Hello World Test' and we can not use a flag to replace all occurrences of Test. After implementing this, we can write 'Hello Test Test' replace /Test/g with 'World which returns 'Hello World World'.

Notes

• regex terminal is defined in https://github.com/jvalue/jayvee/blob/main/libs/language-server/src/grammar/terminal.langium
• flags available https://javascript.info/regexp-introduction
• there are some "regex for regex" examples out there (e.g., https://stackoverflow.com/a/17843773). This seems like it would be an improvement over our current regex regex but still as if it might contain big issues. I'd probably go with the easy regex expression we have right now (using / as delimiter) and just add the gmi flags in addition.

Definitions of Done

• A PR has been opened and accepted
• All user acceptance criteria are met
• All tests are passing