More explicit typing for PendingStateManager.savedOps

[markfields]

Description

Reading through this code, I was uncertain when IPendingMessage.sequenceNumber should/must be present or not. I found that it's actually very unambiguous in practice - it's only used after a local message is processed and moved to the savedOps array. So I updated the typing to reflect that.

Got to remove a runtime assert now that TypeScript is helping.

[msfluid-bot]

⯅ @fluid-example/bundle-size-tests: +269 Bytes

Metric Name	Baseline Size	Compare Size	Size Diff
aqueduct.js	457.46 KB	457.5 KB	⯅ +41 Bytes
azureClient.js	555.23 KB	555.28 KB	⯅ +55 Bytes
connectionState.js	680 Bytes	680 Bytes	■ No change
containerRuntime.js	258.67 KB	258.69 KB	⯅ +20 Bytes
fluidFramework.js	405.94 KB	405.95 KB	⯅ +14 Bytes
loader.js	134.04 KB	134.05 KB	⯅ +14 Bytes
map.js	42.13 KB	42.14 KB	⯅ +7 Bytes
matrix.js	145.61 KB	145.62 KB	⯅ +7 Bytes
odspClient.js	523.37 KB	523.43 KB	⯅ +55 Bytes
odspDriver.js	97.55 KB	97.57 KB	⯅ +21 Bytes
odspPrefetchSnapshot.js	42.61 KB	42.62 KB	⯅ +14 Bytes
sharedString.js	162.62 KB	162.63 KB	⯅ +7 Bytes
sharedTree.js	396.45 KB	396.46 KB	⯅ +7 Bytes
Total Size	3.3 MB	3.3 MB	⯅ +269 Bytes

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Baseline commit: bfbef34ed3db0ed08b03ecdb1de31a3b948fbcdd

Generated by :no_entry_sign: dangerJS against d086bf97fb05ad62e1fb1355a5e16411888b838c

[markfields]

Keeping it alive a little longer...

[microsoft-github-policy-service[bot]]

This PR has been automatically marked as stale because it has had no activity for 60 days. It will be closed if no further activity occurs within 8 days of this comment. Thank you for your contributions to Fluid Framework!