Buggify GRV proxy to return errors and fix bugs found [release 7.1]

[jzhou77]

Cherrypick #7844

Note this will not change to use the new error code grv_proxy_memory_limit_exceeded.

100k 20220811-235034-jzhou-19c1f48e9fc7bb5c passed

Code-Reviewer Section

The general pull request guidelines can be found here.

Please check each of the following things and check all boxes before accepting a PR.

• [ ] The PR has a description, explaining both the problem and the solution.
• [ ] The description mentions which forms of testing were done and the testing seems reasonable.
• [ ] Every function/class/actor that was touched is reasonably well documented.

For Release-Branches

If this PR is made against a release-branch, please also check the following:

• [ ] This change/bugfix is a cherry-pick from the next younger branch (younger release-branch or main if this is the youngest branch)
• [ ] There is a good reason why this PR needs to go into a release branch and this reason is documented (either in the description above or in a linked GitHub issue)

[fdb-windows-ci]

Doxense CI Report for Windows 10

• Commit ID: 581819e438bece9d0d230f7f19872ce8fdf185b8
• Result: :heavy_check_mark: SUCCEEDED
• Build Logs (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: 581819e438bece9d0d230f7f19872ce8fdf185b8
• Duration 0:53:03
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Logs (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-cluster-tests on Linux CentOS 7

• Commit ID: 581819e438bece9d0d230f7f19872ce8fdf185b8
• Duration 1:34:55
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Logs (available for 30 days)

[fdb-windows-ci]

Doxense CI Report for Windows 10

• Commit ID: 6a65f700bed3e8a4f1d5ba72626fbb7ae327a061
• Result: :heavy_check_mark: SUCCEEDED
• Build Logs (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: 6a65f700bed3e8a4f1d5ba72626fbb7ae327a061
• Duration 0:55:40
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-cluster-tests on Linux CentOS 7

• Commit ID: 6a65f700bed3e8a4f1d5ba72626fbb7ae327a061
• Duration 1:31:02
• Result: :x: FAILED
• Error: Error while executing command: if $(grep -q -- "--- FAIL:" ${CODEBUILD_SRC_DIR}/fdb-kubernetes-tests/logs/*.log); then echo "TESTS FAILED SEE THESE LOGS:"; echo ; grep -l -- "--- FAIL:" ${CODEBUILD_SRC_DIR}/fdb-kubernetes-tests/logs/*.log; exit 1; fi. Reason: exit status 1
• Build Logs (available for 30 days)
• Build Artifact (available for 30 days)