Folia-tools

* [alpino2folia] Fixed conversion of dependencies and syntax layer, was missing or a long time due to an unforeseen change in Alpino output (proycon/folia49)
* [foliaspec] Added code generation for new Rust library
* [foliabench] Added a new benchmark tool for the foliapy library, implementing four benchmarks.

Documentation update, added docstrings to all the tools for documentation (automatically harvestable for metadata)

Bugfix release:
* [tei2folia] prevent generating empty folia comments in rare cases (La…
* [tei2folia] fix in t-ref, text ended up outside attribute
* [folialangid] language constraints were not propagated to underlying …
* [folialangid] implemented confidence threshold and fallback language

Minor bugfix release:
* [folialangid] exit code was wrong

* [folialangid] adding support for using a different textclass as source
* [folialangid] fix in conflicting options for folialangid
* [tei2folia] Small adaptation for part annotation and spacing (proycon/folia61)

* [foliamerge] fixing breakage with new library (reported in proycon/flat148)
* [foliaupgrade] exit code was wrong