Expand property references in version property of platform.txt

[cmaglie]

Please check if the PR fulfills these requirements

• The PR has no duplicates (please search among the Pull Requests
  before creating one)
• 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)

• What kind of change does this PR introduce?
  Fix Property references not expanded in version property of platform.txt #1823

• What is the current behavior?
  See Property references not expanded in version property of platform.txt #1823 for reference. CLI crash.

• What is the new behavior?
  The version property is handled correctly.

• Does this PR introduce a breaking change, and is titled accordingly?
  No

[codecov]

Codecov Report

Merging #1830 (860e3b3) into master (869c971) will decrease coverage by 0.02%.
The diff coverage is 40.00%.

@@            Coverage Diff             @@
##           master    #1830      +/-   ##
==========================================
- Coverage   36.29%   36.26%   -0.03%     
==========================================
  Files         232      232              
  Lines       19497    19496       -1     
==========================================
- Hits         7076     7071       -5     
- Misses      11592    11594       +2     
- Partials      829      831       +2     

Flag	Coverage Δ
unit	36.26% <40.00%> (-0.03%)	⬇️

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

Impacted Files	Coverage Δ
arduino/cores/packagemanager/loader.go	71.79% <40.00%> (-0.57%)	⬇️
arduino/cores/packagemanager/package_manager.go	62.18% <0.00%> (-0.85%)	⬇️
internal/integrationtest/arduino-cli.go	80.34% <0.00%> (+1.15%)	⬆️

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

[per1234]

Thanks Cristian!