feat(service): add crud service structure

[theEvilReaper]

Proposed changes

Currently, each model service has its own interface with the same methods defined in it. This duplicates a lot of code and makes the interfaces harder to maintain. The goal of this pull request is to introduce a basic CRUD layer to reduce duplicated method declarations.

Types of changes

What types of changes does your code introduce to this project?
Put an x in the boxes that apply

• Bugfix (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)
• Documentation Update (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of
them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before
merging your code.

• I have read the CONTRIBUTING.md
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

[github-actions]

Test results

 27 files   27 suites   3s ⏱️
 53 tests  41 ✅ 12 💤 0 ❌
159 runs  123 ✅ 36 💤 0 ❌

Results for commit 38a9014.