[FIX] Fix and improve Atlassian Crowd User Sync

[kos4live]

Before the sync was running into a exception of "Cannot read property 'crowdClient' of undefined" and was running on all instances redundant.
Now the described issue was fixed and used SyncedCron with configurable sync interval.

[piotrkochan]

could you get rid of this plain password saved in user document?

[piotrkochan]

Maybe it is good idea to merge these changes with https://gist.github.com/jsternadel/09d2a068343f64146e98f675b20666e7 together?

[steerben]

Nice to see, that it progresses @engelgabriel

[Hudell]

It seems like a good part of this pull request is already implemented on our develop branch now. @kos4live I'm sorry it took us so long to check this, but do you mind comparing your changes to the ones that were merged and check if there's anything missing?

[rodrigok]

@Hudell can you check what is different from our new changes and see if it makes sense?

[rodrigok]

@Hudell ping, can you check this?

[Hudell]

I compared the PR with the existing implementation and with the only exception of a try catch being handled in a different place, it's pretty much the same code.

I'll be closing this one now.