* 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
* new proc to foster different size retention policy implementations
The new proc, decreaseDatabaseSize, will have different implementations
per each driver. For example, in future commits we will implement a size
retention policy thanks to partitions management, in Postgres.
* RetentionPolicy: use of new instead of init for ref object types
* waku_archive: fix signatures in decreaseDatabaseSize methods
* retention_policy_size: minor cleanup of comments and imports
Ivan FB
Darshan K
Hanno Cornelius