[1/N] omdb db sagas: list running and inject fault (#7732)

Breaking apart #4378 and copying the structure of #7695, add `omdb db
saga` as a command and implement the following sub-commands:

    Usage: omdb db saga [OPTIONS] <COMMAND>

    Commands:
      running  List running sagas
        fault  Inject an error into a saga's currently running node

This addresses part of the minimum amount required during a release
deployment:

1. after quiescing (#6804), omdb can query if there are any running
sagas.

2. if those running sagas are stuck in a loop and cannot be drained
(#7623), and the release contains a change to the DAG that causes Nexus
to panic after an upgrade (#7730), then omdb can inject a fault into the
database that would cause that saga to unwind when the affected Nexus is
restarted

Note for 2, unwinding a saga that is stuck in this way may not be valid
if there were significant changes between releases.

Author: jmpesp

Cargo.lock

@@ -52,6 +52,7 @@ serde_json.workspace = true
 sled-agent-client.workspace = true
 slog.workspace = true
 slog-error-chain.workspace = true
+steno.workspace = true
 strum.workspace = true
 supports-color.workspace = true
 tabled.workspace = true
@@ -67,6 +68,7 @@ multimap.workspace = true
 indicatif.workspace = true
 petgraph.workspace = true
 oxnet.workspace = true
+owo-colors.workspace = true
 
 [dev-dependencies]
 camino-tempfile.workspace = true

dev-tools/omdb/Cargo.toml

@@ -159,6 +159,8 @@ use strum::IntoEnumIterator;
 use tabled::Tabled;
 use uuid::Uuid;
 
+mod saga;
+
 const NO_ACTIVE_PROPOLIS_MSG: &str = "<no active Propolis>";
 const NOT_ON_SLED_MSG: &str = "<not on any sled>";
 
@@ -343,6 +345,8 @@ enum DbCommands {
     /// Query for information about region snapshot replacements, optionally
     /// manually triggering one.
     RegionSnapshotReplacement(RegionSnapshotReplacementArgs),
+    /// Commands for querying and interacting with sagas
+    Saga(saga::SagaArgs),
     /// Print information about sleds
     Sleds(SledsArgs),
     /// Print information about customer instances.
@@ -1064,6 +1068,9 @@ impl DbArgs {
                         )
                         .await
                     }
+                    DbCommands::Saga(args) => {
+                        args.exec(&omdb, &opctx, &datastore).await
+                    }
                     DbCommands::Sleds(args) => {
                         cmd_db_sleds(&opctx, &datastore, &fetch_opts, args).await
                     }