Move redundant logic to common util for trace splitting

[devalshahamd]

TraceLens/TraceUtils/*py scripts share some common logic and variables that can be moved to common utils.py file.
Similarly TraceLens/Trace2Tree/trace_capture_merge_experimental.py has some redundant code that can be streamlined.

[devalshahamd]

1. ANNOTATION_PATTERN is duplicated
2. _find_events_by_pattern and _find_events_by_pattern_quiet are very similar
3. get_iter_details_from_name can be used in both scripts.