adding additional Unit3 support in the wrapper: PriorFactorUnit3, Values::insert/update/at(Unit3)

[tmcg0]

This very simple PR adds some additional functionality for the GTSAM wrapper for Unit3 types. Specifically:

• adding PriorFactorUnit3 as a wrapper type
• Adding Values methods update(), insert(), at() that support Unit3 types.

(apologies if there is a good reason this functionality is missing, or if it's added somewhere else that I've missed)

[dellaert]

This is awesome, but check why some of the CI runs fail?

[tmcg0]

Hmm. The code I added was really small and shouldn't have broken anything. I'll try to dig in to why the MacOS CI fails. A quick look at the CI logs makes it look like it's something else going on.

[ProfFan]

It appears to be some compatibility problem on latest boost (which is what brew tracks). I don't have bandwidth now unfortunately.

[tmcg0]

It appears to be some compatibility problem on latest boost (which is what brew tracks). I don't have bandwidth now unfortunately.

Yep. I don't have a Mac, so I likely won't be able to track this down. But it looks like the latest merged PR passed the MacOS CI. I'm a bit confused as how that was passing. Did brew track a new boost in the last four days?

[tmcg0]

The failing CI in this PR should be fixed by the latest PR which fixed some boost compatibility in Brew. Thanks @ProfFan for fixing that!

[ProfFan]

@tmcg0 Glad to help :)

Please merge in or rebase to latest develop to fix CI.

[tmcg0]

Looks like one of the Windows CI timed out after 6 hours. Also looks like that's happening to other recent PRs. I assume this is a known issue or a problem with GitHub's servers?

[ProfFan]

Since it's only the Debug version I think it's timing out. If that is the only blocker then I think it's fine.

[dellaert]

Thanks!!! Very useful :-) And you helped us debug the Mac issue.