Fixing several bugs in the microservice implementation

[Gram21]

This hotfix targets several issues in the microservice implementation that were uncovered recently after the microservice was actually used and initial bugs were fixed in the commits 7b35c21 and 0661657:

1. Bug in the TextImpl.getLength() for the microservice version: The previous version returned the String length, not the number of words.
2. Implementing a POST request (together with the corresponding one in the actual microservice) as long texts exceeded the maximum URI-length (as the text was provided as request parameter), causing a http exception.
3. The JSON schema (and the class) was missing a few POS-tags, causing an exception during deconstruction. At the same time, removed the duplicate PosTag enum as it was basically duplicate code.
4. Improved the performance for some implementation of Text/Word/Phrase/Sentence to use lazy initialization and storing some values instead of calculating them each time.
5. Removed a cyclic dependency in the equals and hashcode of WordImpl of the microservice. Now, the previous and next words are not part of these as otherwise all words of the whole text needs to be compared each time when comparing two words.

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

76.3% Coverage
0.0% Duplication