Rework applicative options

[mwestphal]

Complete refactoring of the options parsing mechanism in F3D application.

Implementation:
- Create a new F3DOptionsTools namespace that declare all app options and corresponding libf3d options and parse CLI
- Expose F3DConfigFileTools and update the config parsing feature
- Rewrite fully F3DStarter to use F3DOptionsTools and F3DConfigFileTools relying on a clear logic

The logic is:
- Parse the CLI once, store the CLI options in a single OptionsDict in a OptionsEntries
- Parse the config file once, store in a OptionEntries
- Update the app and lib options with config < cli logic without a provided filename
- Finish engine, window initialization
- Create a dynamic OptionsDict containing the changed options and emplace in DynamicOptionsEntries
- Update the app and lib options with config < cli < dynamic logic with filename

Other features:
- --input is back as a proper positional cli option!
- --scalars, -s is now split into --scalar-coloring, -s and --coloring-array, with F3D, F3DWeb, libf3d and vtkext related changes
- Add support for using libf3d option names in config
- Add GetClosestOption for configs
- Remove support for f3d --option val, = must be used: jarro2783/cxxopts#211

Fixes: #1569 #434 #1114

In other PRs:

• Add -D --define support: Add a -D --define option to set libf3d options directly #1600
• Add imperative config support: Add imperative config option support #1601

[codecov]

Codecov Report

Attention: Patch coverage is 97.72257% with 11 lines in your changes missing coverage. Please review.

Project coverage is 96.82%. Comparing base (6ef173d) to head (0555a6e).
Report is 5 commits behind head on master.

Files with missing lines	Patch %	Lines
application/F3DSystemTools.cxx	77.27%	5 Missing ⚠️
application/F3DConfigFileTools.cxx	94.33%	3 Missing ⚠️
application/F3DOptionsTools.cxx	98.94%	2 Missing ⚠️
application/F3DStarter.cxx	99.46%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1580      +/-   ##
==========================================
- Coverage   96.85%   96.82%   -0.04%     
==========================================
  Files         107      108       +1     
  Lines        7694     7643      -51     
==========================================
- Hits         7452     7400      -52     
- Misses        242      243       +1     

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[snoyer]

There has been an issue in the past with cxxopts being too eager to split arguments into vectors; #1078 fixed it with a workaround because cxxopts's splitting was needed for point3/vector3/color arguments.
However now that f3d parses vectors itself if would be worth checking if we can disable cxxopts splitting entirely and possibly remove the workaround.

#define CXXOPTS_VECTOR_DELIMITER '\0' would tell cxxopts to split on null and therefore never split.

[mwestphal]

There has been an issue in the past with cxxopts being too eager to split arguments into vectors; #1078 fixed it with a workaround because cxxopts's splitting was needed for point3/vector3/color arguments. However now that f3d parses vectors itself if would be worth checking if we can disable cxxopts splitting entirely and possibly remove the workaround.

#define CXXOPTS_VECTOR_DELIMITER '\0' would tell cxxopts to split on null and therefore never split.

Absolutely correct! --input is back!

[Meakk]

Last minor nitpicking but please change the web app too.