[Manager] Gray out projects in project wizard that are already attached #5190

Job	Run time
libs-build	6m 23s
apps-build	9m 7s
client-armv6-build	3m 18s
libs-cmake-build	6m 56s
client-arm-build	3m 55s
client-arm64-build	3m 31s
client-x86-build	3m 30s
client-x86_64-build	3m 34s
manager-build (assembleRelease)	3m 58s
manager-build (assembleXiaomi_release)	4m 49s
manager-build (assembleArmv6_release)	3m 52s
manager-build (jacocoTestReportDebug)	5m 40s
	58m 33s

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