Update snappy-java and migrate mjson to org.json to address CVEs

[bbimber]

There are CVEs reported for mjson, which does not appear to be an actively maintained project:

https://nvd.nist.gov/vuln/detail/CVE-2023-34611 https://github.com/bolerio/mjson/issues/40

and also snappy-java:

https://nvd.nist.gov/vuln/detail/CVE-2023-34453 https://nvd.nist.gov/vuln/detail/CVE-2023-34455

the latest snappy-java has been patched.

This PR does two things:

• It updates to the latest snappy-java
• It migrates from mjson (which appears to be a dead project) to org.json. From what I can tell mjson wasnt being used for anything other than pretty basic JSON object manipulation. In theory these should function about the same.

[lbergelson]

@bbimber Thank you!

[bbimber]

@lbergelson were there any other changes you needed on this? Also, and this isnt urgent, but is there a defined release schedule on htsjdk? Thanks.

[lbergelson]

Ack, I had it set to rebase instead of squash. Sorry for commit spam.

[lbergelson]

Thanks for doing this. I was thinking of doing a release very soon.