refactor(backend): Rename & move IntegrationCredentialsStore to backend (#8648)

- Move `autogpt_libs.supabase_integration_credentials_store` into
`backend`
   - `.store` -> `backend.integrations.credentials_store`
   - `.types` -> added to `backend.data.model`
- Rename `SupabaseIntegrationCredentialsStore` to
`IntegrationCredentialsStore`

We wanted to get a few security things in quickly in #8403 and had to
make some compromises to do so. This picks those up and fixes them.

- Resolves #8540

### Checklist 📋

#### For code changes:
- [x] I have clearly listed my changes in the PR description
- [x] I have made a test plan
- [x] I have tested my changes according to the test plan:
  <!-- Put your test plan here: -->

---------

Co-authored-by: Reinier van der Leer <pwuts@agpt.co>
Co-authored-by: Aarushi <50577581+aarushik93@users.noreply.github.com>

docs/content/platform/getting-started.md

@@ -128,3 +128,21 @@ By default the application for different services run on the following ports:
 Frontend UI Server: 3000
 Backend Websocket Server: 8001
 Execution API Rest Server: 8006
+
+#### Additional Notes
+
+You may want to change your encryption key in the `.env` file in the `autogpt_platform/backend` directory.
+
+To generate a new encryption key, run the following command in python:
+
+```python
+from cryptography.fernet import Fernet;Fernet.generate_key().decode()
+```
+
+Or run the following command in the `autogpt_platform/backend` directory:
+
+```bash
+poetry run cli gen-encrypt-key
+```
+
+Then, replace the existing key in the `autogpt_platform/backend/.env` file with the new one.

docs/content/platform/new_blocks.md

@@ -113,7 +113,7 @@ Implementing the block itself is relatively simple. On top of the instructions a
 you're going to add a `credentials` parameter to the `Input` model and the `run` method:
 
 ```python
-from autogpt_libs.supabase_integration_credentials_store.types import (
+from backend.data.model import (
     APIKeyCredentials,
     OAuth2Credentials,
     Credentials,