[FEATURE] Enable "Hold AI Transmission" for "Broadcast Parallel"

[iantron]

Is your feature request related to a problem? Please describe. The issue with the current behavior is only for someone flying in a multiplayer environment who is trying to get Vaicom to recognize the keywords in a normal human-to-human radio message. It works well if you plan our your micro-pauses carefully, have good recognition fidelity.

When trying to do this, particularly with "Marking Mom's", vaicom transmits the mm call to the carrier and the carrier starts responding before I'm done with the call. The mm call is somewhat long... approximately "marshall, 101, marking mom's [pause] 100 for 50, angels 10, low state 8.0

Describe the solution you'd like AI Transmission should be held until I release PTT when using "Broadcast Parallel" and "Hold AI Transmission". Currently "Hold AI Transmission" option is grayed out with "Broadcast Parallel" selected. I believe it becomes an option with the other Tx modes.

Describe alternatives you've considered Speaking quicker is an option, but it's still difficult for the longer examples like marking mom's, and it reduces the likelihood of capturing the keyword and increases the likelihood that I have to throw out another "marking mom's" on the radio, which is disruptive.

The other Tx modes help solve the problem, but at the expense of immersion.

Additional context N/A