feat: Add database schema for internal Access API

[SanjayVas]

No description provided.

[wfa-reviewable]

This change is 

[kungfucraig]

Reviewed 7 of 7 files at r1, all commit messages.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @SanjayVas)

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src/main/resources/access/spanner/changelog.yaml line 20 at r1 (raw file):

  - include:
      file: create-access-schema.sql
      relativeToChangeLogFile: true

nit: missing new line

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src/test/kotlin/org/wfanet/measurement/access/deploy/gcloud/spanner/AccessSchemaTest.kt line 28 at r1 (raw file):

class AccessSchemaTest : UsingSpannerEmulator(Schemata.ACCESS_CHANGELOG_PATH) {

  @Test fun `database is created`() {}

Can you assert something or explain why it's not necessary to do so?

[SanjayVas]

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

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src/test/kotlin/org/wfanet/measurement/access/deploy/gcloud/spanner/AccessSchemaTest.kt line 28 at r1 (raw file):

Previously, kungfucraig (Craig Wright) wrote…

Can you assert something or explain why it's not necessary to do so?

Done. Note that this follows the pattern of other schema tests in the repo.

[stevenwarejones]

Reviewed 5 of 7 files at r1, 2 of 2 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @kungfucraig)