fuzz: Rework strong and weak net enum fuzzing

Summary:
The fuzz tests have several problems:

• The array passed to the fuzz engine to pick net_permission_flags is outdated
• The process_message* targets has the service flags as well as connection type hardcoded, limiting potential coverage
• The service flags deserialization from the fuzz engine doesn't allow for easy "exact matches". The fuzz engine has to explore a 64-bit space to hit an "exact match" (only one bit set)

Fix all issues in the commits in this pull

This is a backport of core#20789

Backport differences explained by out-of-order backports:

• we no longer have local_services in ConsumeNode (D14750)
• we no longer have CConnman::SetServices (D12248)

Test Plan: ninja bitcoin-fuzzers

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D15713