Move methods from DomainSets.jl

[jishnub]

Currently, DomainSets.jl performs type-piracy with Domain, so this PR is an attempt to move the pirated methods to this package. This involves adding two lightweight dependencies, and the following is the impact on load times:
On master

julia> @time_imports using IntervalSets
     32.6 ms  IntervalSets

This PR

julia> @time_imports using IntervalSets
      3.7 ms  StaticArraysCore
      2.0 ms  CompositeTypes
     36.1 ms  IntervalSets

Tests remain to be added.

[codecov]

Codecov Report

Base: 99.16% // Head: 80.26% // Decreases project coverage by -18.89% ⚠️

Coverage data is based on head (00f197c) compared to base (0661291).
Patch coverage: 5.00% of modified lines in pull request are covered.

Additional details and impacted files

@@             Coverage Diff             @@
##           master     #127       +/-   ##
===========================================
- Coverage   99.16%   80.26%   -18.90%     
===========================================
  Files           3        4        +1     
  Lines         239      299       +60     
===========================================
+ Hits          237      240        +3     
- Misses          2       59       +57     

Impacted Files	Coverage Δ
src/IntervalSets.jl	95.08% <0.00%> (-3.23%)	⬇️
src/domain.jl	5.35% <5.35%> (ø)

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