Support `$bit` bitwise update operator

[AlekSi]

https://www.mongodb.com/docs/manual/reference/operator/update/bit/

DoD:

• [ ] both pg and Tigris should work
• [ ] compat tests for bitwise and, or, xor
• [ ] compat tests for cases with dot notation
• [ ] compat tests for different data types (e.g. what works, what return errors)
• [ ] compat tests for maxint64 and when it overflows
• [ ] update docs about supported commands

[dcoppa]

Hi! We are developing a product based on Open5Gs. We would like to use FerretDB rather than MongoDB, also for consolidation purposes since we're already using PostgreSQL for other functions of the product (less moving parts the better). Unfortunately this is not possible at the moment, because Open5Gs is using the $bit operator. Do you have an estimation of when this issue will be closed? Thank you

[AlekSi]

I think it should be done in several weeks. Unless, of course, someone will help us implement it.

[adetunjii]

@rumyantseva I would like to take up this issue

[AlekSi]

@adetunjii any news? Anything we could help you with?

[adetunjii]

I've made head way. I'll raise a PR soon

[dcoppa]

Just a quick update: I have compiled FerretDB with the patch from https://github.com/adetunjii/FerretDB/commit/729b63d1b7e668dabdcbb50b1742c9a00983a9d5 and now I have a working Open5Gs setup using FerretDB instead of MongoDB. UEs can access the 5G network and everything seems to work fine. Thanks a lot! Cannot wait for this to land into the main branch ;)