Add 5.05 support; fix FOptionalProperty support for 5.4 #100

Job	Run time
Calculate job matrix	1m 6s
CasePreserving__Shipping__Win64 / build	22m 56s
CasePreserving__Dev__Win64 / build	19m 23s
CasePreserving__Debug__Win64 / build	17m 36s
CasePreserving__Test__Win64 / build	18m 51s
Game__Debug__Win64 / build	20m 7s
Game__Dev__Win64 / build	16m 23s
Game__Shipping__Win64 / build	20m 16s
Game__Test__Win64 / build	17m 57s
LessEqual421__Debug__Win64 / build	21m 5s
LessEqual421__Dev__Win64 / build	17m 44s
LessEqual421__Shipping__Win64 / build	23m 20s
LessEqual421__Test__Win64 / build	18m 11s
report-artifacts	3s
	3h 54m 58s

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