fix(core): make model and respository customizable

[yeshamavani]

now user can use the default as well as their custom respository

GH-121

Description

The mixin now accepts two optional parameters for audit model and repository also now the repositories dont have the tenantGuard() by default it can be binded based on condition

Fixes #121

Type of change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Intermediate change (work in progress)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

Created a sample app and tested that

Checklist:

• [x] Performed a self-review of my own code
• [x] npm test passes on your machine
• [ ] New tests added or existing tests modified to cover all changes
• [x] Code conforms with the style guide
• [x] API Documentation in code was updated
• [ ] Any dependent changes have been merged and published in downstream modules