#1644: added JSON deserialization tests, implement + registered deserializer

[hohwille]

This PR fixes #1644

Implemented changes:

• added PypiObjectJsonDeserializer
• registered in JsonMapping
• simplified our Java model PypiObject to the minimum we really need.
• added tests

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Checklist for this PR

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• When running mvn clean test locally all tests pass and build is successful
• PR title is of the form #«issue-id»: «brief summary» (e.g. #921: fixed setup.bat). If no issue ID exists, title only.
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  with internal

[hohwille]

[ERROR] TomcatUrlUpdaterTest.testTomcatUrlUpdaterCreatesDownloadUrlsAndChecksums:41 » IllegalState Error while getting versions from JSON API https://api.github.com/repos/apache/tomcat/git/refs/tags

See #1475 - bug still not fixed. Unplug your network and run TomcatUrlUpdaterTest. This is as nasty as a virus ;)

[coveralls]

Pull Request Test Coverage Report for Build 20235088356

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 10 unchanged lines in 3 files lost coverage.
• Overall coverage decreased (-0.002%) to 70.138%

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Files with Coverage Reduction	New Missed Lines	%
com/devonfw/tools/ide/json/JsonMapping.java	1	93.33%
com/devonfw/tools/ide/tool/ide/IdeToolCommandlet.java	1	78.33%
com/devonfw/tools/ide/tool/repository/PipRepository.java	8	51.85%

Totals
Change from base Build 20115895339:	-0.002%
Covered Lines:	10160
Relevant Lines:	13921

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💛 - Coveralls