feat: add better error reporting

[anonrig]

Thanks @Yakiyo for reporting the lack of error messages. This would make finding the root cause of the error faster, I assume.

➜  pacquet git:(error-reporting) ✗ cargo run -- init
   Compiling pacquet_cli v0.0.1 (/Users/yagiz/Developer/pacquet/crates/cli)
    Finished dev [unoptimized + debuginfo] target(s) in 0.78s
     Running `target/debug/pacquet init`
Error: pacquet_package_json::already_exist_error

  × initialize package.json
  ╰─▶ package.json file already exists
  help: Your current working directory already has a package.json file.

[codecov-commenter]

Codecov Report

Merging #43 (65db0d3) into main (3e76733) will decrease coverage by 0.98%.
The diff coverage is 27.27%.

@@            Coverage Diff             @@
##             main      #43      +/-   ##
==========================================
- Coverage   81.72%   80.74%   -0.98%     
==========================================
  Files          21       21              
  Lines        1045     1049       +4     
==========================================
- Hits          854      847       -7     
- Misses        191      202      +11     

Files Changed	Coverage Δ
crates/cli/src/commands.rs	24.00% <ø> (ø)
crates/cli/src/lib.rs	43.20% <22.58%> (-11.34%)	⬇️
crates/package_manager/src/commands/install.rs	100.00% <100.00%> (ø)