UDP bug fix and minor interface refactor, fix CLI filter and view command

[tonygallen]

There are 3 changes in this PR.

1. Bug Fix

• Fixes a bug in the UDP decoder (udp_decoder.py) for the t32 format by correctly extracting the on field from the packed y+on value and initializes the offest variable.

2. Added UDP Unit Test

• Added a test that transmits and receives randomly generated events on localhost for both UDP formats and validates the events, including wrapping for the 32-bit timestamp.

3. Refactor UDP packetization interface:

• Replaces the payload_length parameter with events_per_packet in the UDP encoder (udp_encoder.py). It seems to me that payload_length was really the number events per packet , so the I renamed the argument and removed the divisibility check like assert payload_length % 8 == 0.
• Changed the default value for new events_per_packet to 100 to be under the MTU for both formats. (Previous default value was above MacOS limit for UDP packet size 9216 bytes)
• It is worth noting that I seem to get better performance when exceeding the MTU and fragment packets. So perhaps its better to increase the default value?
• Another worthy note is that I occasionally run into UDP socket buffer overflow. Possible solution would be to drop packets when that happens.

[tonygallen]

Added two more commits:

1. Fixes the CLI filter command as in this issue #29 (comment)

• The regularize filter uses typing.Optional[timestamp.TimeOrTimecode] for its start parameter, but this type wasn't handled in the filter parser. Added type annotation checks for TimeOrTimecode and Optional[TimeOrTimecode], mapping them to the existing parse_time and parse_optional_time functions respectively.

2. Fix the CLI view command to work infinite streams

• The view subparser for frame output was missing the --progress argument that other output subparsers have, causing a KeyError when accessing args["progress"]. Also changed the method call from to_viewer() to view() to match the actual API. The fix adds conditional progress argument handling (defaulting to show progress for finite streams, hidden for infinite streams) and properly removes the unused on_progress argument before calling view().

We should add some unit tests for the CLI.