[breaking] Check cross-platform compatibility of sketch names

[MatteoPologruto]

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• The PR has no duplicates (please search among the Pull Requests
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• The PR follows
  our contributing guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• UPGRADING.md has been updated with a migration guide (for breaking changes)
• configuration.schema.json updated if new parameters are added.

What kind of change does this PR introduce?

Documentation enhancement

What is the current behavior?

Sketch names ending with a . can be used. Reserved names can be used as sketch names.

What is the new behavior?

It is no longer possible to name sketches in the above mentioned way.

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

Yes

[codecov]

Codecov Report

Patch coverage: 46.22% and project coverage change: +0.15 🎉

Comparison is base (82e6f5d) 62.90% compared to head (a2aab05) 63.06%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2216      +/-   ##
==========================================
+ Coverage   62.90%   63.06%   +0.15%     
==========================================
  Files         218      220       +2     
  Lines       19452    19481      +29     
==========================================
+ Hits        12237    12285      +48     
+ Misses       6134     6116      -18     
+ Partials     1081     1080       -1     

Flag	Coverage Δ
unit	63.06% <46.22%> (+0.15%)	⬆️

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

Impacted Files	Coverage Δ
arduino/errors.go	27.62% <0.00%> (-0.40%)	⬇️
commands/daemon/daemon.go	28.70% <0.00%> (-0.27%)	⬇️
commands/instances.go	64.70% <ø> (+3.73%)	⬆️
commands/sketch/set_defaults.go	0.00% <0.00%> (ø)
internal/cli/arguments/sketch.go	85.00% <ø> (-3.47%)	⬇️
internal/cli/board/attach.go	25.42% <0.00%> (+2.69%)	⬆️
internal/cli/burnbootloader/burnbootloader.go	45.23% <0.00%> (ø)
internal/cli/monitor/monitor.go	13.07% <0.00%> (ø)
internal/cli/arguments/port.go	46.87% <20.00%> (-4.15%)	⬇️
internal/cli/debug/debug.go	68.13% <40.00%> (-2.33%)	⬇️
... and 5 more

... and 2 files with indirect coverage changes

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Requested changes made. Thanks!