Add right click menu to treeview

[Goz3rr]

To allow for options such as copying name or deleting nodes

[budak7273]

Deleting nodes is implemented. Copying names has yet to be implemented for [O] tags, but is implemented for [E] and [C] tags.

[virusek20]

The only remaining feature is adding objects right now, but that has to wait for the saving rewrite. I didn't consider implementing name copy for [O] tags since they are just helpers to make it easier for the user, they don't represent any actual game object.

[budak7273]

@virusek20 Adding name copy for [O] tags would be helpful in writing lines for Types.xml more quickly.

[virusek20]

I did notice that it was really time consuming to write the type tooltips, I didn't split it into a separate commit, but it's hidden under 8b4fb884f713550a635054cef0e0bf423b371fae Either way, I'm still not closing this because adding doesn't work just yet