[nexus] add alert_list and alert_view external API endpoints - #11072

control: job assigned to worker 01M00KQJ830Q78SHP6TGC9B6Y1 [factory aws, i-0592adbc29a3b72c9] (queued for 53 s)
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task: starting task 0: "setup"
task: process exited: duration 4114 ms, exit code 0
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task: starting task 1: "rust-toolchain"
task: process exited: duration 18491 ms, exit code 0
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task: starting task 2: "authentication"
task: process exited: duration 16 ms, exit code 0
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task: starting task 3: "clone repository"
task: process exited: duration 18099 ms, exit code 0
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task: starting task 4: "build"
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|  Documenting repo-depot-client v0.1.0 (/work/oxidecomputer/omicron/clients/repo-depot-clie [...]
|  Documenting omicron-workspace-hack v0.1.0 (/work/oxidecomputer/omicron/workspace-hack)
|  Documenting omicron-uuid-kinds v0.1.0 (/work/oxidecomputer/omicron/uuid-kinds)
|  Documenting dev-tools-common v0.1.0 (/work/oxidecomputer/omicron/dev-tools/common)
|     Finished `dev` profile [unoptimized + debuginfo] target(s) in 7m 23s
|    Generated /work/oxidecomputer/omicron/target/doc/api_identity/index.html and 203 other  [...]
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| real     7:23.935577178
| user    20:11.372432583
| sys      4:18.392202196
| trap        0.303545517
| tflt        0.035891642
| dflt        0.081166728
| kflt        0.000018960
| lock  7:03:09.762263945
| slp   2:28:51.649707582
| lat        35.118323804
| stop     2:08.334101826
task: process exited: duration 832388 ms, exit code 0
|W| found 0 output files