Add a discovery config flow to Wemo

[balloob]

Description:

Convert Wemo to use config flows and make it discoverable via SSDP integration. I have not touched the rest of the integration, which still uses discovery forwarding. That's for the future.

Checklist:

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

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

• [The manifest file][manifest-docs] 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.

[ghost]

Hey there @sqldiablo, mind taking a look at this pull request as its been labeled with a integration (wemo) you are listed as a codeowner for? Thanks!

This is a automatic comment generated by codeowners-mention to help ensure issues and pull requests are seen by the right people.

[DavidFW1960]

The integration for this shows as:

and no devices.
Changed my Wemo config to just:

wemo:

Is this expected behaviour?

[balloob]

Ah the translations are not there yet :( will be fixed in 95.

Devices are indeed not there, that would require some more restructuring of the Wemo integration.

[scottsuine]

This seemed to break the discovery of Tasmota Sonoff devices that are in Wemo mode. Worked fine up to 0.93, since 0.94 these devices are no longer discoverable by Hassio