Limit Node Depth in Heatmap generation

[Subtractem]

New Feature: User selectable limiter on node depth for Node Power heatmap generation.

Description of the problem being solved:

Currently, generating the full heatmap can take multiple minutes for certain builds on slower machines. In the vast majority of cases the user doesn't care about nodes more than a certain distance away from currently allocated nodes. By giving the user a dropdown to choose to only check against nodes with a max distance we can dramatically speed up the operation.

Too much choice seemed frivolous so I went with only 5 and 10 . We could easily expand this to more choices if we wanted. More than 10 is often close to the entire tree anyway for many builds.

Steps taken to verify a working solution:

Generate a Node Power heat map after selecting from the new dropdown to the right of the checkbox on the Tree Tab.

Link to a build that showcases this PR:

All builds will show this functionality, even no build at all.

Before screenshot:

After screenshot:

[Subtractem]

Discussed with LocalIdentity, I have moved the Import and Export tree buttons to the Manage Trees popup to make room in the TreeTab bar as it is currently overflowing.

[IMKoryakin]

Heya @Subtractem, just wondering why is it a dropdown with just 5 and 10 but not a numericupdown (with min and max values to prevent exceptions)?
May be make steps in that numericupdown like (5,10,15,20...)?
You say its frivolous but I think more options is better than less options :D

When All checkbox is selected - you can probably hide numericupdown to save some space