* bump_dependencies.md: add nim-results dependency
* change imports stew/results to results
* switching to Nim 2.0.8
* waku.nimble: reflect the requirement nim 1.6.0 to 2.0.8
Adding --mm:refc as nim 2.0 enables a new garbage collector that we're
not yet ready to support
* adapt waku code to Nim 2.0
* gcsafe adaptations because Nim 2.0 is more strict
* chore(rln-relay-v2): additional testing
* fix: bump librln to v0.4.2 for v2
* fix: catch possible error from the copyFrom
* ci: rename step title for rln-version
* Allow text/plain content type descriptor for json formatted content body. Refactored duplicated encode/decode functions for rest api
* Fix relay endpoint decodings of content bodies to accept text/plain
* Added support for content body decoder for checking media type if additional parameters are present
* Fix wrong usage of ContentTypeData - appeared only for tests
