Fix command injection due to legacy code

[wargio]

do not squash

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

Fixes a command injection which is triggered by rizin.c when RzBinInfo.rclass is fs and RzBinInfo.bclass contains the payload which is passed to rz_core_cmdf.

This PR also refactors the pebble parser to ensure endianness compatibility on different hosts.