feat(api)(frontend): add task scheduling feature

[mawandm]

Description
This PR introduces the concept of tasks within the API module. A use case for task is running an ingestion pipeline from a datasource.

The result of this PR is that we will not need to current uniform scheduling mechanism. Rather, users are able to pick when to schedule the ingestion of a specific datasource.

Testing this PR
To test this PR,

1. Run the RAG Microservice (Set the env variable NESIS_RAG_EMBEDDING_DIMENSIONS = 384 in order to use HuggingFace's embeddings models)
2. Run the API Microservice
3. Create a session with

curl -X POST -H "Content-Type: application/json"  -k http://localhost:6000/v1/sessions -d '{"email":"test.user@domain.com","password":"password"}'

4. Create a datasource with (Use token from step 3. above

curl -d '{"type": "minio", "name": "cloud-documents", "connection": {"user": "your_username","password": "your_password","endpoint": "http://localhost:59000","dataobjects": "boc"}}' -H "Content-Type: application/json"  -H "Authorization: Bearer <token>" -X POST http://127.0.0.1:6000/v1/datasources

5. Create a task to run immediately with replace parent_id and datasource.id with the datasource id from step 4.

curl -X POST -H "Content-Type: application/json" -H "Authorization: Bearer <token>" -k http://localhost:6000/v1/tasks -d '{"type":"ingest_datasource","parent_id":"<datasource-id>",  "definition":{"datasource":{"id":"<datasource-id>"}}}'

Ingestion should commence shortly

Closes #8