ABC-79: use autocomplete channels endpoint

[ccbrown]

Summary

See mattermost/mattermost#8163 and mattermost/mattermost-redux#384

Won't work until the other PRs are merged.

Ticket Link

https://mattermost.atlassian.net/browse/ABC-79

Checklist

• Ran make check-style to check for style errors (required for all pull requests)
• Ran make test to ensure unit and component tests passed
• Has server changes
• Has redux changes

[jasonblais]

@ccbrown Server-side results not loading for me on channel autocomplete. Client-side results displayed immediately. The test server has 24 channels of which the user-0 account has joined 6.

Network should be fine. Waited for several seconds. Other channel searches seem fine.

[mattermod]

Setup Test Server label detected. Spinmint test server created if build succeeds (checks pass and no conflicts with base branch).

[mattermod]

Spinmint test server created at: http:https://i-0aa0065b1b13eeba7.spinmint.com

Test Admin Account: Email: [email protected] | Password: user-0

Test User Account: Email: [email protected] | Password: user-1

[ccbrown]

@jasonblais Had to update redux after its PR was merged. This spinmint is good to test now.

[jasonblais]

@ccbrown This looks good to me. The difference in perf is great. It was usable at even slow 3G connection.

It's hard to say if users would notice the difference when returning X arbitrary results instead of the first X.. I personally didn't when I tested. And given it's standard in other apps I suspect users wouldn't.

One issue though: Off-Topic channel always shows at the top of my "Other Channels" list:

[jasonblais]

One minor note above about Off-Topic

[ccbrown]

@jasonblais I'm not sure I see the problem. The user wasn't in the off-topic channel. So it should have been there, right? I just joined the off-topic channel and it was moved from the "other channels" list as expected.

[ccbrown]

Oh. I guess you're referring to the sorting. Yeah, it looks like capitalized channel names are sorted before lowercase. That would be a server-side fix though, not part of this PR.

[ccbrown]

Here's the PR to fix that: mattermost/mattermost#8176

[amyblais]

The new PR (mattermost/mattermost#8176) is now merged.

[jasonblais]

That's good then, @ccbrown we can merge this PR