Added --install-in-builtin-dir flag to lib install command

[cmaglie]

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What kind of change does this PR introduce?

Adds --install-in-builtin-dir flag to lib install command.

What is the current behavior?

What is the new behavior?

When the --install-in-builtin-dir flag is set, the libraries are installed in the directory specified by the directories.builtin.libraries configuration setting:

directories:
  builtin.libraries: /home/user/.....

The libraries installed inside the builtin directory are not automatically upgraded via lib upgrade. They can be upgraded anyway, by forcing an install of an already installed library.

Does this PR introduce a breaking change, and is titled accordingly?

No

Other information

[codecov]

Codecov Report

Base: 36.64% // Head: 36.60% // Decreases project coverage by -0.04% ⚠️

Coverage data is based on head (4410d08) compared to base (53a6f25).
Patch coverage: 0.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2077      +/-   ##
==========================================
- Coverage   36.64%   36.60%   -0.04%     
==========================================
  Files         229      229              
  Lines       19471    19491      +20     
==========================================
  Hits         7135     7135              
- Misses      11498    11518      +20     
  Partials      838      838              

Flag	Coverage Δ
unit	36.60% <0.00%> (-0.04%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
commands/lib/install.go	0.00% <0.00%> (ø)
internal/cli/lib/install.go	0.00% <0.00%> (ø)

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