Add SigNoz access review driver

Add a SigNoz connector so its organization members can be pulled into
access-review campaign snapshots. SigNoz authenticates with a
SIGNOZ-API-KEY admin service-account key and a customer-supplied base
URL (a SigNoz Cloud region/tenant host or a self-hosted instance).

The driver lists users via GET /api/v1/user, which returns the role
(ADMIN/EDITOR/VIEWER) inline so admin detection works in a single call,
and maps the SigNoz user status (active / pending_invite / deleted) to
the account active flag. The name resolver reads the organization
display name from GET /api/v2/orgs/me to title the access source.

Wire the provider through the coredata enum and settings, the
connector-provider registry (driver and name-resolver factories), the
console API-key input schema and validation, the access-review source
label, and the SigNoz brand logo.

Co-authored-by: Bryan FRIMIN <bryan@frimin.fr>
Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/coredata/migrations/20260529T062100Z.sql

@@ -0,0 +1,15 @@
+-- Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted, provided that the above
+-- copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+-- REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+-- AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+-- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+-- LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+-- OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+-- PERFORMANCE OF THIS SOFTWARE.
+
+ALTER TYPE connector_provider ADD VALUE IF NOT EXISTS 'SIGNOZ';