Solve some bugs in the broadlink switch

[Danielhiversen]

Description:
If several broadlink devices are used, the learn service should be given separate names.
The learn service is also only needed for rm devices.

The other bugs I have seen have to wait until @mjg59 has merged these prs: https://github.com/mjg59/python-broadlink/pulls/Danielhiversen

Related issue (if applicable): fixes parts of #4997

Checklist:

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

• Local tests with tox run successfully. Your PR cannot be merged unless tests pass
• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.