Tree based acceleration for polygon clipping / boolean ops

[asinghvi17]

Spun out of #259
Parent: #273 (algorithm passthrough in clipping)
Child PRs: none so far, you've hit the leaf node!

Can use STRtrees (expensive to construct, efficient to query) or Natural trees (from tg, cheap to construct, ~same query speed for our usecases)

There are three methods here:

• naive, n*m nested loop
• loop over all edges of a, tree on b
• dual tree query on trees from a and b

This algorithm should be easily portable to s2 when that becomes available - and the structure allows e.g. manifold passthrough as well.

---

This PR also adds a LoopStateMachine module that basically just defines an Action wrapper struct, and a macro that can take care of that action wrapper struct.

With this macro, a function running within a loop can return Break() or Continue() which indicates to the caller that it should break or continue.

E.g.:

f(i) = i == 3 ? Break() : i
count = 1
for i in 1:5
    count = @processloopaction f(i)
end
count # 2

---

TODOs:

• add rejection tests for duplicate points
• add lopsided single tree query
• add dual tree query
• figure out good heuristics for when to choose which
• establish tree construction and query benchmarks on various cases
• port the tg benchmarks here
• add more tests and benchmarks with complex polygons

[asinghvi17]

• Tree based acceleration for polygon clipping / boolean ops #274 : 3 dependent PRs (#278 , #283 , #285 ) 👈 (View in Graphite)
• Algorithm + manifold and accelerator passthrough in clipping functions #273
• Spatial tree interface #297
• Convert the orient predicate to AdaptivePredicates + minor predicate changes #275
• Add a TGGeometry extension for fast inexact geometric predicates #271 : 1 other dependent PR (#291 )
• [Core] Add an algorithm interface + StableTasks #269 : 1 other dependent PR (#282 )
• main

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