Choose between multiple remotes instead of showing an error

[Chris2011]

If you have add more than one remote and you want to push an untracked branch, NetBeans just shows an error that it can't choose the correct remote due to many remotes.

I added this for push to upstream and pull from upstream. If we have multiple remotes, it just opens the same UI for pull/push and preselect the current branch.

For push it will also ask for setting this branch tracked to the remote branch. I have a problem for doing the same for pull. I guess it is a thread thing.

Inside of PullAction in the method perform, it never hits the finally block, due to removing the threadlocal variable inside the runWithoutInding method. I dunno whether this is a bug but for me it feels like that. So I couldn't test it.

The PR is not finished yet, but you already can have a look and left comments please.

PR approval and merge checklist:

1. Was this PR correctly labeled, did the right tests run? When did they run?
2. Is this PR squashed?
3. Are author name / email address correct? Are co-authors correctly listed? Do the commit messages need updates?
4. Does the PR title and description still fit after the Nth iteration? Is the description sufficient to appear in the release notes?

If this PR targets the delivery branch: don't merge. (full wiki article)

[Chris2011]

I will do a correct squash and merge at the end. Unfortunately I merged master after my commit. Sry for that.

[Chris2011]

I also added a null check, due to a NPE throwing. I see failing tests, I will fix them soon.