Feat/ab#54365 self service endpoints

[ketanreliefapps]

Description

create endpoint for Self-service

• mutation to add layer
• mutation to edit layer
• mutation to delete layer
• query to get single layer
• queries to get multiple layers

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Improvement (refactor or addition to existing functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

currently frontend is not ready, so you are able to test by postman/playground

Checklist:

• * My code follows the style guidelines of this project
• * Linting does not generate new warnings
• * I have performed a self-review of my own code
• * I have commented my code, particularly in hard-to-understand areas
• * I have put JSDoc comment in all required places
• * My changes generate no new warnings
• * I have included screenshots describing my changes if relevant
• * I have selected labels in the Pull Request, according to the changes with code brings
• I have made corresponding changes to the documentation ( if required )
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules