Edit issue title

[BrianLitwin]

This has three pieces of key functionality:

• sends a v3 network request to update the issue title
• updates the IssueTitleSectionController (the title the user sees
  when they open an Issue)
• updates the Issue Timeline

These can be tested/verified manually. I also added a unit test
to verify that the User's interaction with the EditIssueTitleViewController
works as expected, eg a network request won't be sent unless a user
edits the issue title and calls onSave().

This is an update of #2348 - in this version of the PR,
EditIssueTitle's behavior is intended to be very similar to
Labels, People, and Milestones. Ie it updates the UI optimistically and
these updates are triggered by ContextMenuWillDismiss().

I didn't add any functionality to update Bookmarks after an
issue title is edited because my understanding is that the
bookmark titles are not persisted locally anymore but are retrieved from
the github api.

I updated some string constants (requested in original pr) and I removed the
width parameter from a helper function titleStringSizing because
it was convenient and I couldn't find anywhere that parameter was used

[BrianLitwin]

Just a note @rnystrom @Sherlouk @Huddie or anybody who can help: I have NO IDEA what's going on with the noise in .pbxproj on this pr ... All I know is that it was very difficult to add a new file to 'local pods`. Lmk if y'all have any solutions or ideas.

[Huddie]

@BrianLitwin still on this? I can take a look @ .pbxproj if you are. See if I can think of something.
Landing this would be sweet

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[BrianLitwin]

@Huddie The feature works fine locally but I haven't been able to add files to the GitHub pod without a ton of noise in my PR. If you wanna check it out and see if you can fix, that'd be great.

[Huddie]

@BrianLitwin I think the files are fine here. Seems like a lot of random stuff but I'm getting the same thing when I try it out. I removed the commit and re-ran the project and the same proj file is getting generated. @BasThomas want to take a quick look?
@BrianLitwin Maybe just resolve the conflict and we can merge it in. Works for me on my local and if Bas takes a look it may be good to go.

[BasThomas]

Would be awesome to get this in indeed. I’ll take another look when I get the time!

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[BasThomas]

🤔 why did you close this one @BrianLitwin?

[BrianLitwin]

@BasThomas on accident lol

[rswgnu]

So is anyone going to add this? Really need to be able to edit issue titles. Thanks.

[BasThomas]

Well, feel free to help us push this forward :-)

In the meantime, you can edit titles via the GitHub web interface.

[Huddie]

I think the only thing holding this up atm is just the merge conflict. Brian wasn’t sure why one file was showing a weird number of changes but I don’t think there’s an issue there. Should be fine once reviewed and conflicts are resolved

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[rswgnu]

All I typically need is the web interface title edit. Somehow I had overlooked that button. Thanks. Bob