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

control: job assigned to worker 01M00KQNHW4VPXJR36FCAFAVC3 [factory aws, i-0291259fdf7776174] (queued for 1 m 3 s)
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task: starting task 0: "setup"
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task: starting task 1: "rust-toolchain"
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task: process exited: duration 102273 ms, exit code 0
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