Add support for IR format protocol version 0.0.2 except for gracefully ignoring UtcOffsetChange packets

[Henry8192]

References

clp UtcOffsetChange PR

Description

As mentioned in the reference, clp now has a UtcOffsetChange packet in its IR stream. This PR ignores this packet so that log viewer won't give out errors when opening this format.

To properly handle this, a TIMESTAMP_UTC_OFFSET_CHANGE tag is added to PROTOCOL.js with value 0x3F. TIMESTAMP_NULL and TIMESTAMP_NULL_VAL are removed accordingly because:

1. No one is currently using these variables;
2. The current value of TIMESTAMP_NULL conflicts with the new value TIMESTAMP_UTC_OFFSET_CHANGE.

Then in FourByteClpIrStreamReader.js, _readLogEvent catches TIMESTAMP_UTC_OFFSET_CHANGE tag and then drop the 64 bit packet.

Validation performed

• Successfully loaded a four-byte IR v0.0.2 compressed file (decompress four-byte.clp.zst.zip to four-byte.clp.zst first)
• Successfully loaded a IR v0.0.1 file