Add testing Dockerfile and add to CI #1109

Job	Run time
Check CI Clearance	0s
CI Start Gate	0s
Build .deb Package	0s
Check winget-pkgs Pull Request Template is up to date	0s
Build Windows Installer .exe	0s
Build DMAPI	0s
Build Docker Image	0s
Linux Tests	0s
Build gh-pages	0s
Windows Tests	0s
Linux Live Tests	0s
Windows Live Tests	0s
OpenAPI Spec Validation	0s
Upload Code Coverage	0s
CI Completion Gate	0s
Deployment Start Gate	0s
Deploy HTTP API	0s
Deploy Nuget Packages	0s
Deploy DreamMaker API	0s
Ensure TGS Release is Latest GitHub Release	0s
Deploy TGS	0s
Regenerate Changelog	0s
Deploy TGS (PPA)	0s
Deploy TGS (Docker)	0s
Deploy TGS (winget)	0s
	0s

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