core/cmd: port /R commands to the rzshell

[giridharprasath]

SQUASH ME

Your checklist for this pull request

• I've read the guidelines for contributing to this repository
• I made sure to follow the project's coding style
• I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

• Inital Port command yaml changes

Test plan

...

Closing issues

...

[ret2libc]

What is the issue related to this? Why under i (which is usually for binary-related info)? I think there's something like this already under /R.

[XVilka]

Agree, they should be in the /R commands, just put them into:

• librz/core/cmd_descs/cmd_search.yaml
• librz/core/cmd/cmd_search_rop.c (this one should be updated from the old handlers to use the new handlers.

Moreover, I also recommend adding TABLE output, with more information about each gadget

[giridharprasath]

Still WIP:

• Fix memory leaks
• Add table view for gadget
• Regex filter is broken, should be fixed.

[XVilka]

Thanks, much better now!

[giridharprasath]

Some notes:

• /Rk is unusable, Will be refactoring it and adding testcases for it in a separate PR.
• Current table view with only columns:

[0x08048330]> /Rt
addr bytes disasm 
------------------

Please lmk if any other fields needed to be added which would be helpful in table mode. @XVilka

[XVilka]

Some notes:

* `/Rk` is unusable, Will be refactoring it and adding testcases for it in a separate PR.

* Current table view with only columns:

[0x08048330]> /Rt
addr bytes disasm 
------------------

Please lmk if any other fields needed to be added which would be helpful in table mode. @XVilka

Should be enough for now. Further improvements could be done when necessary.

[XVilka]

Looks good overall, please address my feedback first though