[release-8.0] Preserve the first uncopied backup log version on timeout

[tclinkenbeard-oai]

Backports #14119 to release-8.0.

When backup log copying times out, finish copying the current version and resume at the first omitted version. Stop both nested result loops at that boundary so later groups cannot overwrite the continuation version and skip mutations. Includes the three upstream regression tests.

Patch-release compatibility: protocol versions, RPC serialization, backup log key/value formats, task version 1, and the existing nextBeginVersion parameter encoding are unchanged. Older and newer agents can read the same persisted tasks. This is an unmodified cherry-pick of the upstream patch.

Validation: source compatibility audit, formatting, and git diff --check pass. Both fdbclient_test and fdbserver build successfully. All 3 /backup/copy-log-continuation tests pass in native and Sim2 modes. tests/fast/BackupToDBCorrectness.toml passes with its consistency check (seed 14119, buggify on).

[foundationdb-ci]

Result of foundationdb-pr-clang on Linux RHEL 9

• Commit ID: 9049709
• Duration 0:45:13
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-clang-arm on Linux RHEL 9

• Commit ID: 9049709
• Duration 0:47:45
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-macos-m1 on macOS 14.x

• Commit ID: 9049709
• Duration 0:54:09
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-cluster-tests on Linux RHEL 9

• Commit ID: 9049709
• Duration 1:42:43
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)
• Cluster Test Logs zip file of the test logs (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-macos on macOS 14.x

• Commit ID: 9049709
• Duration 3:06:13
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux RHEL 9

• Commit ID: 9049709
• Duration 0:52:45
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)