SWMMVis worker + API backports on stock EPA SWMM 5.2.4

Pinned by openswmm.gui/cmake/EngineVersions.cmake (OPENSWMM_ENGINE_524_TAG).
Parity vs stock v5.2.4: 133/133 .out byte-identical. Worker vs runswmm with
the running-continuity getter on every step: 12/12 identical .out and .rpt.

Merge pull request HydroCouple#121 from HydroCouple/swmm6_rel

Fix build issues

Merge pull request HydroCouple#87 from HydroCouple/swmm6_rel

Fixing bugs surfacing from running legacy EPA Routing Tests

Merge pull request HydroCouple#73 from HydroCouple/swmm6_rel

Building python wheels for release

Update build-and-test.yml

Update benchmark to v2.4.0

Bump version

Merge pull request HydroCouple#99 from USEPA/release

Release

Merge pull request USEPA#91 from USEPA/release

Master <- Release

Update build-and-test.yml

Update release tag for benchmark

Processing update swmm v5.1.15 (HydroCouple#61)

In addition to improvements described in ReleaseNotes this PR includes: 
 - Improvements to cmake build system
 - Testing scripts previously found in /tools have migrated to their own repo
 - Support for GitHub Actions has been added