Feature: Add --m3 option for advanced minification

[MathieuSoysal]

Summary

Add a new CLI option --m3 to CG-Bundler.

Details

• The --m3 flag should perform all actions of the current --m2 minification (aggressive minify with whitespace replacements).
• In addition, --m3 should also minify function names and variable names in the bundled output.
• The goal is to further reduce the output size and obfuscate code, making reverse engineering more difficult.

Motivation

Users who want maximum minification would benefit from a mode that shortens identifiers as well as whitespace.

Acceptance Criteria

• New --m3 CLI flag is recognized by the tool.
• When used, output has function and variable names minified in addition to the --m2 effects.
• Adequate tests are provided for this new feature.
• Documentation is updated to describe the new flag.

For reference, see how --m2 is currently handled in the project: README.md