[dbsql] [ffapi] DB Stats and Metrics

[onelapahead]

Redo of #205

We nabled build info metrics and have ffapi tests to ensure the metrics endpoint works as expected.

DB metrics are in two forms:

1. stats collector wraps Stats() from *sql.DB with basic gauges around conn settings and pool usage
   instrumentation of all operations and transactions
2. Similar to ffresty, there's then a global func for clients to enable DB metrics, ensuring all initialized databases in a process are metered by the collector and instrumentation.

[EnriqueL8]

Seems like a race condition on this one

time="2026-04-09T12:23:09Z" level=info msg=Disconnected wsc=9d80c11c-4fa6-4678-8c32-dbe517fe0592
fatal error: concurrent map iteration and map write

goroutine 100 [running]:
github.com/hyperledger/firefly-common/pkg/wsserver.(*webSocketServer).Close(...)
	/home/runner/work/firefly-common/firefly-common/pkg/wsserver/wsserver.go:130
github.com/hyperledger/firefly-common/pkg/wsserver.TestBroadcastStartWithoutConnections(0xc0003a64e0?)
	/home/runner/work/firefly-common/firefly-common/pkg/wsserver/wsserver_test.go:389 +0x2d0
testing.tRunner(0xc0003a64e0, 0xaf11e0)
	/opt/hostedtoolcache/go/1.23.12/x64/src/testing/testing.go:1690 +0xf4
created by testing.(*T).Run in goroutine 1
	/opt/hostedtoolcache/go/1.23.12/x64/src/testing/testing.go:1743 +0x390

[EnriqueL8]

This should fix it #214