Release Notes v1.2

Upgrade Notes

Implement PELL token bridging functionality from service chain to pell chain
Enhance sorting stability by implementing sort.SliceStable to maintain relative ordering of equal elements
Implement genesis import/export functionality for operator shares
Bump contract to v0.2.30, implement reentrant sync group, and introduce upgrade system contract transaction type
Resolve pagination issue in pool sync group functionality
Address sync group inconsistencies related to operator registration data handling
Resolve xmsg migration issues in keygen process and optimize TSS procedure
Fix the issue where the outbound pending nonce tracker is not being deleted