Add MyECLPay invoices system (#887)

## Description

### Summary

<!--Brief description of what this PR does.-->
<!--Don't explain the code, justify what this PR exists for!-->

<!--Sources/references at the end-->

### Issues to be resolved

<!-- If applicable-->
<!--Use keywords "closes", "fixes", "resolves", or others at
https://docs.github.com/en/get-started/writing-on-github/working-with-advanced-formatting/using-keywords-in-issues-and-pull-requests
-->

<!--Fixes #-->
<!--Fixes aeecleclair/CalypSSO#-->

### Required PRs

<!-- If applicable-->
<!--Use keywords "depends on" or "blocked by", see
https://github.com/gregsdennis/dependencies-action -->

<!--Depends on #-->
<!--Depends on aeecleclair/CalypSSO#-->

### Changes Made

<!--Please describe the changes made in this pull request-->
<!--Tell the big steps, use a checklist to show progress. You can
explain here how the code works.-->

- [x] ...
- [ ] ...

### Additional Notes

<!--Anything relevant that does not quite fit in the summary-->

<details>
<summary>

## Classification

</summary>

### Type of Change

- [ ] 🐛 Bug fix (non-breaking change which fixes an issue)
- [x] ✨ New feature (non-breaking change which adds functionality)
- [ ] 🔨 Refactor (non-breaking change that neither fixes a bug nor adds
a feature)
- [ ] 🔧 Infra CI/CD (changes to configs of workflows)
- [ ] 💥 BREAKING CHANGE (fix or feature that require a new minimal
version of the front-end)

- [ ] 😶‍🌫️ No impact for the end-users

### Impact & Scope

- [ ] Core functionality changes
- [x] Single module changes
- [ ] Multiple modules changes
- [x] Database migrations required

- [ ] Other: <!--not module-oriented-->

### Testing

- [ ] 1. Tested this locally
- [x] 2. Added/modified tests that pass the CI
- [ ] 3. Tested in a pre-prod

- [ ] 0. Untestable (exceptionally), will be tested in prod directly

### Documentation

- [ ] Updated [the docs](docs.myecl.fr) accordingly : <!--[Docs#0 -
Title](https://github.com/aeecleclair/myecl-documentation/pull/0)-->
- [ ] `"` Docstrings
- [ ] `#` Inline comments

- [ ] No documentation needed

</details>

---------

Co-authored-by: Marc-Andrieu <[email protected]>

Author: Rotheem

app/core/myeclpay/coredata_myeclpay.py

@@ -0,0 +1,9 @@
+from uuid import UUID
+
+from app.types.core_data import BaseCoreData
+
+
+class MyECLPayBankAccountHolder(BaseCoreData):
+    """Bank account holder information for MyECLPay."""
+
+    holder_structure_id: UUID