[Recorded Future] Handle properly playbook alerts errors to not block the connector

[helene-nguyen]

Proposed changes

• Handle properly playbook alerts errors to not block the connector
• Remove assertions and replace with if/else condition for non-blocking solution to catch the error
• Change TLP values to have default RED
• Complete documentation
• Remove unused methods

Related issues

• [RecordedFuture] The connector stops ingesting data if an error (401, 403, ...) occurs while ingesting RF Alerts playbooks #3195
• Change Recorded Future TLP values #3095

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality using different use cases
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

[flavienSindou]

Thanks for the great work.

I made minor comments and suggestions but nothing blocking in my opinion.

[flavienSindou]

Thanks for this runtime data validation .

I think that get_config_variable already has this option thanks to the arg required=True

[helene-nguyen]

Changes have been added, thanks @flavienSindou :)