fw/target: detect module variations in TargetInfo

- Add modules entry to TargetInfo
- When retrieving TargetInfo from cache, make sure info modules match
  those for the current target, otherwise mark info as stale and
  re-generate.

wa/commands/postgres_schemas/postgres_schema.sql

@@ -1,4 +1,4 @@
---!VERSION!1.3!ENDVERSION!
+--!VERSION!1.4!ENDVERSION!
 CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
 CREATE EXTENSION IF NOT EXISTS "lo";
 
@@ -78,6 +78,7 @@ CREATE TABLE Targets (
     oid uuid NOT NULL,
     run_oid uuid NOT NULL references Runs(oid),
     target text,
+    modules text[],
     cpus text[],
     os text,
     os_version jsonb,

wa/commands/postgres_schemas/postgres_schema_update_v1.4.sql

@@ -0,0 +1,2 @@
+ALTER TABLE targets ADD COLUMN modules text[];
+