fix: resolve missing users in <UserCombobox /> (#21822)

Closes #21044

This pull-request addresses an issue we were seeing where we would
attempt to filter the `<UserCombobox />` by the users username or email
not their username (which the rendered options would show).

To highlight this I created three different users. Each with a username
that did not contain their `email` or `name` and attempted to filter.
Attempting to search for `John` wouldn't actually show the user as his
username was `x`, and infact whereas a subset of users might be returned
from the backend for having `john` in the `email` it would've been
filtered by the frontend for not being in the `name` field.

| Name | Username |
| --- | --- |
| `Jake` | `z` |  
| `Jeff` | `y` |
| `John` | `x` |

| Previously | Now |
| --- | --- |
| <img width="560" height="547" alt="OLD_USER_COMBOBOX"
src="https://github.com/user-attachments/assets/a0567264-0034-42ac-aba0-95b05c4f92dd"
/> | <img width="580" height="548" alt="NEW_USER_COMBOBOX"
src="https://github.com/user-attachments/assets/1aa0c942-d340-4b1c-8dde-b97879525bfb"
/> |

coderd/database/queries/users.sql

@@ -247,7 +247,7 @@ WHERE
 		ELSE true
 	END
 	-- Start filters
-	-- Filter by name, email or username
+	-- Filter by email or username
 	AND CASE
 		WHEN @search :: text != '' THEN (
 			email ILIKE concat('%', @search, '%')
@@ -255,6 +255,12 @@ WHERE
 		)
 		ELSE true
 	END
+	-- Filter by name (display name)
+	AND CASE
+		WHEN @name :: text != '' THEN
+			name ILIKE concat('%', @name, '%')
+		ELSE true
+	END
 	-- Filter by status
 	AND CASE
 		-- @status needs to be a text because it can be empty, If it was