Add Github Action check to make sure template UI is unchanged #2969

Job	Run time
Build Examples	1m 38s
photonclient-check-lint	43s
photon-build-all	1m 45s
photonclient-build	1m 5s
Photonlib - Build Docker - Athena	1m 26s
Photonlib - Build Host - Win64	1m 29s
photonserver-build-offline-docs	1m 0s
Photonlib - Build Docker - Raspbian	1m 25s
wpiformat	21s
Photonlib - Build Host - Linux	1m 38s
Photonlib - Build Docker - Aarch64	1m 26s
photonserver-check-lint	48s
Build fat JAR - ${{ matrix.artifact-name }}	1s
Build image - ${{ matrix.image_url }}	1s
photon-release	1s
	14m 47s

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