refactor: Extract listResources utility function for handling pagination

[SanjayVas]

This also fixes an issue where EventGroupsServiceTest was waiting for a real 30s deadline to pass.
Also fixes the simulator issue of PR #1927:
The MC and EDP simulators were only reading the first page of results from ListEventGroups. This means that in environments with more EventGroups, not all test EventGroups would be read. This is exacerbated by #1916, as the default page size is now smaller.

[SanjayVas]

CC @roaminggypsy

[wfa-reviewable]

This change is 

[tristanvuong2021]

Reviewed 11 of 11 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @SanjayVas)

[stevenwarejones]

Reviewed 7 of 11 files at r1, 4 of 4 files at r2, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @SanjayVas)

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src/main/kotlin/org/wfanet/measurement/common/api/grpc/ListResources.kt line 66 at r2 (raw file):

      coroutineContext.ensureActive()

      val resourceList: ResourceList<T> = list(nextPageToken, remaining)

why not just do

val resourceList = list(nextPagetoken, remaining).take(remaining-resourceList.size)

[SanjayVas]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @stevenwarejones)

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src/main/kotlin/org/wfanet/measurement/common/api/grpc/ListResources.kt line 66 at r2 (raw file):

Previously, stevenwarejones (Steven Ware Jones) wrote…

why not just do

val resourceList = list(nextPagetoken, remaining).take(remaining-resourceList.size)

The items that are returned must match the page token that is returned so that the end caller can store the page token and use it for subsequent requests. Therefore it is an error to return fewer items than where the next page token would start from.

[stevenwarejones]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @SanjayVas)

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src/main/kotlin/org/wfanet/measurement/common/api/grpc/ListResources.kt line 66 at r2 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

The items that are returned must match the page token that is returned so that the end caller can store the page token and use it for subsequent requests. Therefore it is an error to return fewer items than where the next page token would start from.

I guess that's a difference in perceived usage. I think the function should cease to return a pageToken once the limit is reached.

[SanjayVas]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @stevenwarejones)

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src/main/kotlin/org/wfanet/measurement/common/api/grpc/ListResources.kt line 66 at r2 (raw file):

I think the function should cease to return a pageToken once the limit is reached.

That is strictly incorrect, as it gives no signal that there are items beyond the limit. The implementation must return a next page token in this case.

[SanjayVas]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @stevenwarejones)

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src/main/kotlin/org/wfanet/measurement/common/api/grpc/ListResources.kt line 66 at r2 (raw file):

Previously, SanjayVas (Sanjay Vasandani) wrote…

I think the function should cease to return a pageToken once the limit is reached.

That is strictly incorrect, as it gives no signal that there are items beyond the limit. The implementation must return a next page token in this case.

To clarify, this function is intended to be used to implement pagination, not just to call a paginated method. e.g. one List method impl calling another, or a UI that wants to display full pages of a specific size.

[stevenwarejones]

Reviewed 3 of 3 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @SanjayVas)

[renjiezh]

I accidentally merged #1927 into this branch instead of main branch.
The PR description has been updated to reflect #1927.

[renjiezh]

Reviewed 6 of 11 files at r1, 2 of 4 files at r2, 3 of 3 files at r3, 3 of 3 files at r4, 1 of 1 files at r5, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @SanjayVas)