Fix capstone-disassemble command and documentation

[theguy147]

Fix capstone-disassemble command and documentation

Description/Motivation/Screenshots

As part of #693 this PR fixes the documentation and help messages for the capstone-disassemble command. Furthermore the command was not working in use cases like emulating aarch64 inside qemu. This was due to an uncaught exception caused in gef_get_auxiliary_values when gdb's info auxv doesn't return useful results. This bug has been fixed. Also resolving of LOCATIONs has been fixed.

With this PR I also propose changing the syntax for the location argument back to how it was before argparse: as a positional argument.

During this PR I introduced a new convenience wrapper function around gdb's parse_and_eval to specifically resolve LOCATIONs. This way other commands can rely on it without having to handle the different possible cases neccessary (because e.g. gdb resolves registers different from symbols and for symbols a simple conversion to int does not work directly). This new function does not aim at replacing gef_safe_parse_and_eval at this point because too many commands rely currently rely on it and there might be use cases that don't resolve locations.

I also added a unit test that checks if resolving a symbol (e.g. "main") works for the command.

How Has This Been Tested?

Architecture	Yes/No	Comments
x86-32	✔️
x86-64	✔️
ARM	✔️
AARCH64	✔️
MIPS	✖️
POWERPC	✖️
SPARC	✖️
RISC-V	✖️
make test	✔️

Checklist

• My PR was done against the dev branch, not master.
• My code follows the code style of this project.
• My change includes a change to the documentation, if required.
• My change adds tests as appropriate.
• I have read and agree to the CONTRIBUTING document.

[hugsy]

Good PR, some stuff to change and we'll merge after. Thanks for updating the doc too.

[theguy147]

I think all requested changes have been implemented now.

[hugsy]

LGTM

[Grazfather]

LGTM. Just a few comment nitpicks.