Move some Diff Options into config

[akiramusic000]

Some options in the Diff Options menu would fit better in the objdiff.json config, since they depend on the project being used, and not the user. Some examples are:

• Arch Settings/ARM/Architecture version
• Arch Settings/ARM/VFPv2 instructions
• Arch Settings/MIPS/ABI
• Arch Settings/MIPS/Instruction category
• Demangler
• Combine data sections
• Combine text sections

A similar approach to how Reverse function order (-inline deferred) is handled could be taken, where a value can be optionally defined in the config, and if no value is specified, leave it up to the user.

[LagoLunatic]

Agreed, this would be useful. Preferred string encoding and maybe Function relocation diffs could be included as well. Though I'm not sure how it would work in edge cases where the user has to override the per-project default as Reverse function order currently appears to become greyed out and unselectable.