fix(login): user discovery - ignore case for loginname, email (#10475)

# Which Problems Are Solved

The new login UI user case sensitive matching for usernames and email
addresses. This is different from the v1 login and not expected by
customers, leading to not found user errors.

# How the Problems Are Solved

The user search is changed to case insensitive matching.

# Additional Changes

None

# Additional Context

- reported by a customer
- requires backport to 4.x

---------

Co-authored-by: Livio Spring <livio.a@gmail.com>

apps/login/src/lib/zitadel.ts

@@ -771,7 +771,7 @@ const LoginNameQuery = (searchValue: string) =>
       case: "loginNameQuery",
       value: {
         loginName: searchValue,
-        method: TextQueryMethod.EQUALS,
+        method: TextQueryMethod.EQUALS_IGNORE_CASE,
       },
     },
   });
@@ -782,7 +782,7 @@ const EmailQuery = (searchValue: string) =>
       case: "emailQuery",
       value: {
         emailAddress: searchValue,
-        method: TextQueryMethod.EQUALS,
+        method: TextQueryMethod.EQUALS_IGNORE_CASE,
       },
     },
   });