[IMPROVEMENT] Ignore version check on mxf essence container

[aipsvrr]

In raising this pull request, I confirm the following (please check boxes):

• I have read and understood the contributors guide.
• I have checked that another pull request for this purpose does not exist.
• I have considered, and confirmed that this submission will be valuable to others.
• I accept that this submission may not be used, and the pull request closed at the will of the maintainer.
• I give this submission freely, and claim no ownership to its content.
• I have mentioned this change in the changelog.

My familiarity with the project is as follows (check one):

• I have never used CCExtractor.
• I have used CCExtractor just a couple of times.
• I absolutely love CCExtractor, but have not contributed previously.
• I am an active contributor to CCExtractor.

---

{pull request content here}

[aipsvrr]

Hi,
There is an issue when subtitles are present in mxf asset but couldn't extracted because defined in code mxf_caption_essence_container (MXF_CT_ANC) has version '9' and one from asset I met has another version. By ignoring version byte (in case of mxf) srt extracts successfully.
So an idea of current PR is to ignore version of mxf caption essence container as it is allowed by smpte standard ("6.3 KLV Coding"):
Note: SMPTE ST 336 specifies that KLV parsers can ignore the version number or use the version number as an additional guide and consistency check in the process of parsing a KLV Key.
Thanks!

[cfsmp3]

LGTM but can you add it to the CHANGELOG as well? It's noteworthy.

[aipsvrr]

Hi @cfsmp3 ,
Sure! Changelog updated.
Thanks!