[Feature] Blueprint-based spawn_actor function for CarlaDataProvider

[Daraan]

Description

Currently when one wants to spawn an Actor from a blueprint this is only possibly via the World object.
There is no addition to the hidden CarlaDataProvider._carla_actor_pool and CarlaDataProvider.register_actor must be called manually.

This PR adds an analogue version, which always adds the actor to the pool for cleanup and if not specified otherwise calls register_actor on Vehicles and Walkers.

def spawn_actor(bp, spawn_point, must_spawn=False, track_physics=None, attach_to=None, attachment_type=carla.AttachmentType.Rigid)

Where has this been tested?

• Platform(s): Ubuntu 22.04
• Python version(s): Python 3.10
• Unreal Engine version(s): ...
• CARLA version: ...

Possible Drawbacks

Possible Changes

Possibly favor a second .try_spawn_actor instead of must_spawn=False.

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This change is 

[glopezdiest]

Reviewed 2 of 2 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @Daraan)

[glopezdiest]

Everything looks good for this PR. A simple yet useful new way to spawn actors that doesn't break anything. Approved