Reapply "Graph total bootstrap time" with fixes to postgres query

[tgnottingham]

Reapply #957 with fixes to postgres query. Fixes #961.

[tgnottingham]

Diff from #957:

diff --git a/database/src/pool/postgres.rs b/database/src/pool/postgres.rs
index c2a67b65..27a4974a 100644
--- a/database/src/pool/postgres.rs
+++ b/database/src/pool/postgres.rs
@@ -359,11 +359,11 @@ impl PostgresConnection {
                 get_rustc_compilation: conn.prepare("
                         select aid, min(total)
                         from (
-                            select aid, sum(duration) as total
+                            select aid, cast(sum(duration) AS bigint) as total
                             from rustc_compilation
                             where aid = any($1)
-                            group by cid
-                        )
+                            group by aid, cid
+                        ) as duration_per_aid_cid
                         group by aid
                     ").await.unwrap(),
                 get_rustc_compilation_by_crate: conn.prepare("

• as duration_per_aid_cid was required because subqueries must have an alias.
• aid was added to the group by because it's just the correct thing.
• cast was added because summing bigint durations produces a numeric duration, and we want an integer duration.

[rylev]

Ran this locally with postgres and it bootstrapped without error. 🚢