perf(tree): avoid cloning change enricher checkout on every change

[yann-achard-MS]

Description

Before this PR, commits were enriched between their application to the local checkout and their sending to the service. This required keeping a defensive clone of the enricher checkout so that it could enrich a commit based on the state immediately before that commit was applied.

This PR change the old order of operations (apply-enrich-submit) to enrich-apply-submit. This allows the enrichment to be performed based on the forest and detached field index of the top-level checkout instead of a clone, thus making cloning necessary only in resubmit scenarios.

While the above sounds simple, it prompted a lot of changes to accommodate the intricacies of transactions. A subsequent PR (perhaps after GA if it is deemed to destabilizing) could clean up a lot of this complexity by making transactions less special throughout the system.

Breaking Changes

None

[msfluid-bot]

⯅ @fluid-example/bundle-size-tests: +4.16 KB

Metric Name	Baseline Size	Compare Size	Size Diff
aqueduct.js	453.27 KB	453.27 KB	■ No change
azureClient.js	552.46 KB	552.46 KB	■ No change
connectionState.js	680 Bytes	680 Bytes	■ No change
containerRuntime.js	256.95 KB	256.95 KB	■ No change
fluidFramework.js	357.8 KB	359.88 KB	⯅ +2.08 KB
loader.js	134.34 KB	134.34 KB	■ No change
map.js	41.53 KB	41.53 KB	■ No change
matrix.js	143.75 KB	143.75 KB	■ No change
odspClient.js	520.83 KB	520.83 KB	■ No change
odspDriver.js	97.3 KB	97.3 KB	■ No change
odspPrefetchSnapshot.js	42.16 KB	42.16 KB	■ No change
sharedString.js	160.27 KB	160.27 KB	■ No change
sharedTree.js	357.78 KB	359.86 KB	⯅ +2.08 KB
Total Size	3.19 MB	3.2 MB	⯅ +4.16 KB

---

Baseline commit: acd340733e4f8c8ac41a9e8b383eb2e134cd7bf5

Generated by :no_entry_sign: dangerJS against d6d916826b80424bafd882d63bb7be9e0f1a11eb