Add Quick Fix code actions to Entity Model Definition File validations

[niveathika]

Description:

Usability is much improved if we add a Quick fix in the above scenario to remove import prefix.

Likewise, all other validations can be improved by suggesting suitable fixes.

[niveathika]

Possible code actions are documented in https://docs.google.com/spreadsheets/d/1GIQJ_34AkFF0pmfGnUGPh78KwWkM_U8rYpPy17xiDiM/edit#gid=15982427

PR with the above code actions can be found in ballerina-platform/module-ballerina-persist#139

[niveathika]

Improvements that can be done on top of the above is,

1. Remove import prefix -> Rename all prefix related types
2. Add supported types -> Include time related types

[niveathika]

Closing this issue as improvements are tracked in #4151