feat: improve error formatting

[phm07]

This PR adds additional error handling and formatting for invalid_input errors. See #1075 for more details.

Before:

$ hcloud server create --name "a a" --image debian-12 --type cpx11
hcloud: invalid input in field 'name' (invalid_input, ca050180d7ec9473)

After:

$ hcloud server create --name "a a" --image debian-12 --type cpx11 
hcloud: invalid input in field 'name' (invalid_input, ca050180d7ec9473)
- name: Name must be a valid hostname.

~~Note: As we are not inside the hcloud-go package we can't access the internal Correlation ID. Since invalid input errors are user errors we probably don't need them anyway.~~

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 87.50000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 70.46%. Comparing base (b937e5c) to head (fd54021). Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/cmd/util/util.go	87.50%	2 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1080      +/-   ##
==========================================
+ Coverage   70.43%   70.46%   +0.02%     
==========================================
  Files         243      243              
  Lines       10722    10738      +16     
==========================================
+ Hits         7552     7566      +14     
- Misses       2505     2507       +2     
  Partials      665      665              

Flag	Coverage Δ
e2e	51.80% <0.00%> (-0.11%)	:arrow_down:
unit	63.84% <87.50%> (+0.03%)	:arrow_up:

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