GroupVerify: Verification page, overrides and public Verified tags

Shown only where GroupVerify is: staff get the Verification page once its gv_* tables are in
the database, and the public site shows "Verified" only while it's on (enabled, with a group)
and not missing from css_plugins list, which the poller reads once a minute over RCON.

- Verification page: plugin state and version, Steam group, saved member list, overrides.
- Overrides (@zio/verify, not on yourself unless Root): give, change, remove; player drawer
  shows why a player is or isn't verified.
- Root sets the group and turns it on/off: saved to gv_settings, and sent as css_gv_* when the
  plugin is loaded so it applies at once.
- gv_* times use GroupVerify's own timezone setting.
- MySQL integration test (SAW_TEST_DSN), unit tests for plugin list parsing and the show rule.

internal/web/assets/common.js

@@ -125,6 +125,9 @@ function statusTag(p) {
 }
 
 const COMM_LABEL = { GAG: "Gag", MUTE: "Mute", SILENCE: "Silence" };
+
+// Verified by GroupVerify: in the server's Steam group, or given an override by staff.
+const VERIFIED_TAG = '<span class="tag verified" title="In the server\'s Steam group, or verified by staff">Verified</span>';
 const COMM_HELP = { GAG: "Text chat blocked", MUTE: "Voice blocked", SILENCE: "Text and voice blocked" };
 
 function segmented(name, value, options) {