* 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
* on_chain/group_manager: use .async: (raises:[Exception]).
* bump nim-dnsdisc
* update nim-chronos to the latest state
* chat2.nim: catch any possible exception when stopping
* chat2bridge.nim: make it to compile after vendor bump
* ValidIpAddress (deprecated) -> IpAddress
* vendor/nim-libp2p additional bump
* libwaku: adapt to vendor bump
* testlib/wakunode.nim: adapt to vendor bump (ValidIpAddress -> IpAddress)
* waku_node: avoid throwing any exception from stop*(node: WakuNode)
* test_confutils_envvar.nim: ValidIpAddress -> IpAddress
* test_jsonrpc_store: capture exception
* test_rln*: handling exceptions
* adaptation to make test_rln_* to work properly
* signature enhancement of group_manager methods
