Request for merging HLKX during HLKX Generation

[kostyanf14]

Based on #641 (comment) and #641 (comment)

Need to implement 2 independent modes:

1. Merge during testing. AutoHCK merge provided HLKX packages during the final creation of the HLKX package
2. Merge only run. AutoHCK merge provided HLKX packages into one package without starting HLK clients and run any testing