Revert "reorder fields in MerkleRoot struct"

[RyanRHall]

Motivation

Avoid forcing breaking changes on RMN nodes

Solution

This reverts commit da570c5.

[github-actions[bot]]

LCOV of commit 9c8d7b6 during Solidity Foundry #8052

Summary coverage rate:
  lines......: 97.6% (2156 of 2208 lines)
  functions..: 94.9% (408 of 430 functions)
  branches...: 93.4% (513 of 549 branches)

Files changed coverage rate: n/a

[cl-sonarqube-production[bot]]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube