Add fan support to lutron_caseta

[djj211]

Breaking Change:

Description:

Adding lutron caseta fan component using pylutron_caseta 0.5.1
Changes. Handle None returned from pylutron_caseta. Updates to use built in fan constants from pylutron_caseta.
Note: This is a re-pull of #24770 which could not be merged due to pylutron_caseta being abandoned. The project is up and running and ready to go.
Note: The PR for updating pylutron_caseta is here #28886 and must go hand and hand with this one.

Related issue (if applicable): fixes #

Pull request with documentation for home-assistant.io (if applicable): home-assistant/home-assistant.io#9780

Example entry for configuration.yaml (if applicable):

lutron_caseta:
  host: 192.168.1.1
  keyfile: ./config/lutron/caseta.key
  certfile: ./config/lutron/caseta.crt
  ca_certs: ./config/lutron/caseta-bridge.crt

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass
• [X ] There is no commented out code in this PR.
• I have followed the development checklist

If user exposed functionality or configuration variables are added/changed:

• [X ] Documentation added/updated in home-assistant.io

If the code communicates with devices, web services, or third-party tools:

• The manifest file has all fields filled out correctly. Update and include derived files by running python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[mdonoughe]

@balloob requested a small refactor on #28886 which you'll need to account for here if that merges first.

[djj211]

@MartinHjelmare Modifications completed. Note I added an additional mapping for FAN_MEDIUM_HIGH: SPEED_MEDIUM. Found a bug when testing out the changes in this PR. When setting the fan speed the mediumhigh directly on the switch, it would cause an error because I did not map the additional lutron speed.

It will seem that we need to revisit the concepts outlined in this architectural issue here as this seems to be a common occurrence for fan components: home-assistant/architecture#127

[MartinHjelmare]

Looks great!

[MartinHjelmare]

@mdonoughe Ok to merge?

[mdonoughe]

lgtm