Add a general xAPI validation option for the command `validate`

[wilbrdt]

Feature Request

Is your feature request related to a problem or unsupported use case? Please describe.
Right now, we are validating xAPI statements against our xAPI models implemented in Ralph.

Describe the solution you'd like
We could imagine that we would want to validate xAPI statements for profiles not defined in Ralph (we won't ever have all the profiles implemented in Ralph).
We could make a general xAPI validation, which checks that actor, id, object and verb are present.
We could use the LaxStatements pydantic model.
The command could be:
bin/ralph validate -f xapi to validate generic xAPI format, and bin/ralph validate -f xapi --full to validate against profiles?
or
bin/ralph validate -f xapi --generic and bin/ralph validate -f xapi --full

Discovery, Documentation, Adoption, Migration Strategy
Of course, documentation would need an update.

[quitterie-lcs]

Why not using the BaseXapiStatement model rather than the LaxStatements ?

[wilbrdt]

You're right, it's preferable to use BaseXapiStatement instead of LaxStatements that was created for a performance purpose