tidy(tree): comments and other nits

[DLehenbauer]

Addressing some deferred PR feedback (comments, spelling and internal renaming)

[msfluid-bot]

⯅ @fluid-example/bundle-size-tests: +2 Bytes

Metric Name	Baseline Size	Compare Size	Size Diff
aqueduct.js	446.18 KB	446.18 KB	■ No change
connectionState.js	680 Bytes	680 Bytes	■ No change
containerRuntime.js	239.26 KB	239.26 KB	■ No change
loader.js	178.73 KB	178.73 KB	■ No change
map.js	48.06 KB	48.06 KB	■ No change
matrix.js	141.84 KB	141.84 KB	■ No change
odspDriver.js	90.27 KB	90.27 KB	■ No change
odspPrefetchSnapshot.js	41.9 KB	41.9 KB	■ No change
sharedString.js	162.75 KB	162.75 KB	■ No change
sharedTree2.js	263.21 KB	263.21 KB	⯅ +2 Bytes
Total Size	1.72 MB	1.72 MB	⯅ +2 Bytes

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Baseline commit: 105c818

Generated by 🚫 dangerJS against 520298f