fix: correctly "or"-join ldap userfilters (#9855)

# Which Problems Are Solved

LDAP userfilters are joined, but as it not handled as a list of filters
but as a string they are not or-joined.

# How the Problems Are Solved

Separate userfilters as list of filters and join them correctly with
"or" condition.

# Additional Changes

None

# Additional Context

Closes #7003

---------

Co-authored-by: Marco A. <kwbmm1990@gmail.com>

internal/idp/providers/ldap/session_test.go

@@ -49,31 +49,31 @@ func TestProvider_userFiltersToSearchQuery(t *testing.T) {
 		name     string
 		fields   []string
 		username string
-		want     string
+		want     []string
 	}{
 		{
 			name:     "zero",
 			fields:   []string{},
 			username: "user",
-			want:     "",
+			want:     []string{},
 		},
 		{
 			name:     "one",
 			fields:   []string{"test"},
 			username: "user",
-			want:     "(test=user)",
+			want:     []string{"(test=user)"},
 		},
 		{
 			name:     "three",
 			fields:   []string{"test1", "test2", "test3"},
 			username: "user",
-			want:     "(test1=user)(test2=user)(test3=user)",
+			want:     []string{"(test1=user)", "(test2=user)", "(test3=user)"},
 		},
 		{
 			name:     "five",
 			fields:   []string{"test1", "test2", "test3", "test4", "test5"},
 			username: "user",
-			want:     "(test1=user)(test2=user)(test3=user)(test4=user)(test5=user)",
+			want:     []string{"(test1=user)", "(test2=user)", "(test3=user)", "(test4=user)", "(test5=user)"},
 		},
 	}
 	for _, tt := range tests {