Gather all collection listeners and changes at the same time

[bdraco]

Proposed change

I noticed the zone integration was taking a bit longer to load than
expected when I added more zones.

This builds on the improvements in #34783 to gather all the changes at once.

Before

2020-10-27 23:52:48 INFO (MainThread) [homeassistant.setup] Setup of domain zone took 3.9 seconds
2020-10-27 23:53:18 INFO (MainThread) [homeassistant.setup] Setup of domain zone took 3.8 seconds
2020-10-27 23:53:53 INFO (MainThread) [homeassistant.setup] Setup of domain zone took 4.0 seconds

After

2020-10-27 23:54:48 INFO (MainThread) [homeassistant.setup] Setup of domain zone took 2.8 seconds
2020-10-27 23:55:17 INFO (MainThread) [homeassistant.setup] Setup of domain zone took 2.7 seconds
2020-10-27 23:55:41 INFO (MainThread) [homeassistant.setup] Setup of domain zone took 2.8 seconds

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

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• This PR fixes or closes issue: fixes #
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[balloob]

Very nice! It doesn't matter for how long I have been writing code, I keep making the same type of mistakes 😅

[bdraco]

Very nice! It doesn't matter for how long I have been writing code, I keep making the same type of mistakes 😅

We all do.