Add ResultStore search to Updater.

[michelle192837]

Initial commit that adds some logic and basic unit tests for these functions.

Will follow up with further changes once I verify this works against a real API.

[google-oss-prow[bot]]

Skipping CI for Draft Pull Request. If you want CI signal for your change, please convert it to an actual PR. You can still manually trigger a test run with /test all

[michelle192837]

/assign @chases2 @sultan-duisenbay

I know this is a long change (apologies!), let me know if I should break it up for easier reviewing. ^^

[google-oss-prow[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: michelle192837, sultan-duisenbay

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/GoogleCloudPlatform/testgrid/blob/master/OWNERS)~~ [michelle192837,sultan-duisenbay] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[michelle192837]

/retest

[michelle192837]

/hold cancel