Integrate bug fixes from fork

[Ayoub Kaanich]

Feel free to integrate some bug fixes from the https://github.com/Technica-Engineering/vector_blf fork

Namely:

• https://github.com/Technica-Engineering/vector_blf/commit/6fd734b45967ebebcdef24c42ea9f72992e845da
• https://github.com/Technica-Engineering/vector_blf/commit/22415ebbf6e55246fc0f54fd28d3b766ff1ff3a6
• https://github.com/Technica-Engineering/vector_blf/commit/02f0a2fe1f7915da1e24025869b98f6d15de937b

The bugs reported above causes the BLF reader to stop mid-file, due to reading incorrect number of bytes.

Issues mostly caused by reader not being compatible with latest BLF specifications.