chore: rename git_auth to external_auth in our schema (#9935)

* chore: rename `git_auth` to `external_auth` in our schema

We're changing Git auth to be external auth. It will support
any OAuth2 or OIDC provider.

To split up the larger change I want to contribute the schema
changes first, and I'll add the feature itself in another PR.

* Fix names

* Fix outdated view

* Rename some additional places

* Fix sort order

* Fix template versions auth route

* Fix types

* Fix dbauthz

coderd/database/queries/externalauth.sql

@@ -0,0 +1,38 @@
+-- name: GetExternalAuthLink :one
+SELECT * FROM external_auth_links WHERE provider_id = $1 AND user_id = $2;
+
+-- name: GetExternalAuthLinksByUserID :many
+SELECT * FROM external_auth_links WHERE user_id = $1;
+
+-- name: InsertExternalAuthLink :one
+INSERT INTO external_auth_links (
+    provider_id,
+    user_id,
+    created_at,
+    updated_at,
+    oauth_access_token,
+    oauth_access_token_key_id,
+    oauth_refresh_token,
+    oauth_refresh_token_key_id,
+    oauth_expiry
+) VALUES (
+    $1,
+    $2,
+    $3,
+    $4,
+    $5,
+    $6,
+    $7,
+    $8,
+    $9
+) RETURNING *;
+
+-- name: UpdateExternalAuthLink :one
+UPDATE external_auth_links SET
+    updated_at = $3,
+    oauth_access_token = $4,
+    oauth_access_token_key_id = $5,
+    oauth_refresh_token = $6,
+    oauth_refresh_token_key_id = $7,
+    oauth_expiry = $8
+WHERE provider_id = $1 AND user_id = $2 RETURNING *;