Add 'Copy instruction bytes' to disassembly context menu

[frmdstryr]

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 updated the documentation with the relevant information (if needed)

Detailed description

This adds a "Copy instruction bytes" to the disassembly widget's context menu. Mainly as a shortcut to search for uses of an instruction (in my case use of an IO port).

Test plan (required)

Right click on an instruction and copy the bytes. Check that the asm matches.

Closing issues

[XVilka]

@frmdstryr by the way, I noticed you work also on ESIL support in your plugin. I don't recommend spending time on this since we are sunsetting ESIL in favor of RzIL:

• ESIL to RZIL conversion rizin#2080
• https://github.com/rizinorg/rizin/blob/dev/doc/rzil.md

[frmdstryr]

Ok, I will start looking at moving to that, thank you.

[XVilka]

@frmdstryr I added an issue to track the C166 support. PRs to the mainstream are welcome since it's relatively popular architecture in the past: rizinorg/ideas#53