Add docs for required minimal permissions of the fdbbackup and backup_agent

[johscheuer]

See title. I think it would be useful for the community to see what permissions are required without going through the code (especially since the HTTP API is not a 1:1 mapping of the permissions).

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[foundationdb-ci]

Result of foundationdb-pr-clang on Linux CentOS 7

• Commit ID: b7fba23
• Duration 0:11:04
• Result: ❌ FAILED
• Error: Error while executing command: ninja -v -C build_output -j ${NPROC} all packages strip_targets. Reason: exit status 1
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr on Linux CentOS 7

• Commit ID: b7fba23
• Duration 0:11:08
• Result: ❌ FAILED
• Error: Error while executing command: ninja -v -C build_output -j ${NPROC} all packages strip_targets. Reason: exit status 1
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-clang-ide on Linux CentOS 7

• Commit ID: b7fba23
• Duration 0:21:26
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-clang-arm on Linux CentOS 7

• Commit ID: b7fba23
• Duration 0:43:53
• Result: ❌ FAILED
• Error: Error while executing command: ninja -v -C build_output -j ${NPROC} all packages strip_targets. Reason: exit status 1
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-macos-m1 on macOS Ventura 13.x

• Commit ID: b7fba23
• Duration 0:45:10
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of foundationdb-pr-macos on macOS Ventura 13.x

• Commit ID: b7fba23
• Duration 0:50:01
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

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

• Commit ID: b7fba23
• Duration 0:57:45
• Result: ✅ SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)
• Cluster Test Logs zip file of the test logs (available for 30 days)

[jzhou77]

Do you intend to add links to [KMS]?