[BUGFIX] Input timers were being started before output finished on Asterisk composed prompts
[BUGFIX] Input initial timers were being started on Asterisk composed prompts even if the prompt was barged
Optimise Asterisk ComposedPrompt's audio termination

Output was being interrupted on Asterisk composed prompts at every DTMF keypress, even if the output was already finished
Merge branch 'feature/ast_composed_prompt_timers' into develop