Use single method to open/close flyout

[ericholscher]

Fixes #541

[agjohnson]

Lit provides a native way to update dependent attributes/variables on reactive property changes. We should use that pattern instead of relying on manually calling methods like this. With willUpdate(), the current code would be fine

https://lit.dev/docs/components/lifecycle/#willupdate

[humitos]

Take a look at the tests I wrote and try to write a test case for this case. These cases where we need to interact with the elements to do QA are pretty hard to notice after deploy otherwise.

[ericholscher]

Cool... I'm a little lost in general with all of this, so might take a while to get back to this.

[humitos]

@ericholscher let me know if I can help here or if you want me to take over it.

[ericholscher]

Feel free to run with it. It was just a small bug I wanted to fix, but the PR feedback seems to require a ton of research that I don't have energy for currently.

[ericholscher]

I think this is still a bug, and this PR makes things better, but I'm going to close it since folks didn't want to ship it.

[humitos]

This is still a bug and Anthony opened a bye issue for it. It's not that we don't want to ship it, there is feedback about how to use the framework to solve this issue that wasn't addressed: #542 (comment)

[agjohnson]

This logic that we have here now might also be the cause of #585. If we aren't always using the magic helpers _open/_close to open/close, updates to properties will be inconsistent like this. Using willUpdate avoids this and allows this.opened = false to always update related attributes.

[ericholscher]

Yea, it's definitely the same issue as #585.