Switch arg parsing to clap v4 with derive

[tranzystorekk]

Should make the code slightly more maintainable. Did my best to preserve old behavior, e.g. flags overriding themselves.

Notes:

• clap 4 no longer colors the help prompt
• clap 4 displays flags in help in the order they are defined in code
• changed some value names to be more descriptive

---

TODO

• Use cargo fmt
• Add necessary tests
• Add changelog entry
• Update default config/theme in README (if applicable)
• Update man page at lsd/doc/lsd.md (if applicable)

[codecov-commenter]

Codecov Report

Merging #818 (2d01c90) into master (ea56a7c) will increase coverage by 0.78%.
The diff coverage is 97.87%.

@@            Coverage Diff             @@
##           master     #818      +/-   ##
==========================================
+ Coverage   86.57%   87.35%   +0.78%     
==========================================
  Files          44       44              
  Lines        4507     4272     -235     
==========================================
- Hits         3902     3732     -170     
+ Misses        605      540      -65     

Impacted Files	Coverage Δ
src/app.rs	39.28% <ø> (-46.19%)	⬇️
src/main.rs	29.41% <0.00%> (+3.09%)	⬆️
src/flags/blocks.rs	96.26% <96.29%> (+0.31%)	⬆️
src/flags/date.rs	96.32% <96.66%> (+2.66%)	⬆️
src/flags/recursion.rs	96.29% <97.56%> (+0.37%)	⬆️
src/display.rs	81.90% <100.00%> (ø)
src/flags.rs	96.77% <100.00%> (ø)
src/flags/color.rs	93.10% <100.00%> (+1.83%)	⬆️
src/flags/dereference.rs	100.00% <100.00%> (ø)
src/flags/display.rs	98.03% <100.00%> (-0.08%)	⬇️
... and 17 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[zwpaper]

hi @tranzystorek-io, thanks so much for sending this big PR!

I have glanced at it mostly, and it lgtm in a glance. @meain what do you think about upgrading to v4, if you have not other concern we can play some attention on this and done the migration

[tranzystorekk]

Heh, sorry for submitting a large chunk of changes like that, I got slightly carried away once I started drafting the code

[meain]

@zwpaper If it looks good to you feel free you merge :D.

[zwpaper]

I have checked most of the code, it mostly looks good to me, and I will test it locally and merge if no problems occurred