prepare and cut ICS v3

[MSalopek]

Problem

Prepare and cut ICS v3 which uses cosmos-sdk v0.47 and ibc-go v7.

Closing criteria

• merge feat/upgrade-ics-sdk47-ibc7 into main
• (chore: bump v2 to v3 #1043) update code and go.mod to reference interchain-security/v3 instead of interchain-security/v2
• create release/v3.x.x branch
• (chore: add release/v3.0.x targets for bots #1046)update branch protection rules an CI workflow files to also track release/v3.x.x
• create changelog for v3.0.0
• create first release candidate v3.0.0-rc0
• resolve: refactor ICS v3 slash packet handling #1105 -> not resolved, issue remains open since it required nuanced changes to CCV protocol
• cut final v3.0.0 -> Release

Problem details