Add UUID config to simulator visual sensors

[Skylion007]

Motivation and Context

Fixes #471

How Has This Been Tested

With existing sensors tests as well as by overriding the UUID

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist

• My code follows the code style of this project.
• [] My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
• I have added tests to cover my changes.
• All new and existing tests passed.

[eundersander]

Can you document how and why to use this somewhere in the code? Even just linking to #471 in the code would help.

Otherwise LGTM.

[mathfac]

Thank you, Aaron! That's longstanding issue for defining several sensors of the same type.

Maybe worth to change Sensor class to fix it once:

habitat-lab/habitat/core/simulator.py

Line 66 in 8cc6cf7

self.uuid = self._get_uuid(*args, **kwargs)

To something like this:

         if self.config and hasattr(self.config, "UUID"):
               self.uuid = config.UUID
        else:
               self.uuid = self._get_uuid(*args, **kwargs)

[mathfac]

This all can be done with:

Suggested change

	return self.uuid
	return self.uuid
	if hasattr(self.config, "UUID"):
	return config.UUID
	else:
	return "rgb"

[Skylion007]

@mathfac Maybe we should just deprecate _get_uuid and have it be a required part of the YAML sensor config?

[Skylion007]

@mathfac Actually, I am not sure I like this method because calling _get_uuid will return the wrong UUID. We really should remove the internal method INMO