Refactor and cleanup CLI module

[juhoinkinen]

Changes:

• Move the helper functions & decorators to a new cli_util.py module (as commented in Support for batch suggest operations for CLI commands #663 (comment))
• Use dict instead of collections.OrderedDict
• Make docs-limit option a common decorator
• Add a few docstrings to helper functions
• Cosmetic fix for unnecessarily split strings
• Mark internal helper functions of cli_util.py as private with underscore
• Simplify helper function to set the project config file path

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[codecov]

Codecov Report

Base: 99.56% // Head: 99.56% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (d1a5043) compared to base (3e8f42f).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #675   +/-   ##
=======================================
  Coverage   99.56%   99.56%           
=======================================
  Files          87       88    +1     
  Lines        6158     6171   +13     
=======================================
+ Hits         6131     6144   +13     
  Misses         27       27           

Impacted Files	Coverage Δ
annif/cli.py	99.62% <100.00%> (-0.08%)	⬇️
annif/cli_util.py	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.