[GITEA] Allow user to select email for file operations in Web UI

- Add a dropdown to the web interface for changing files to select which
Email should be used for the commit. It only shows (and verifies) that a
activated mail can be used, while this isn't necessary, it's better to
have this already in place.
- Added integration testing.
- Resolves https://codeberg.org/forgejo/forgejo/issues/281

(cherry picked from commit 564e701f40)
(cherry picked from commit de8f2e03cc)
(cherry picked from commit 0182cff12e)
(cherry picked from commit 9c74254d46)

models/user/email_address_test.go

@@ -4,6 +4,7 @@
 package user_test
 
 import (
+	"fmt"
 	"testing"
 
 	"code.gitea.io/gitea/models/db"
@@ -309,3 +310,37 @@ func TestEmailAddressValidate(t *testing.T) {
 		})
 	}
 }
+
+func TestGetActivatedEmailAddresses(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+
+	testCases := []struct {
+		UID      int64
+		expected []*user_model.ActivatedEmailAddress
+	}{
+		{
+			UID:      1,
+			expected: []*user_model.ActivatedEmailAddress{{ID: 9, Email: "user1@example.com"}, {ID: 33, Email: "user1-2@example.com"}, {ID: 34, Email: "user1-3@example.com"}},
+		},
+		{
+			UID:      2,
+			expected: []*user_model.ActivatedEmailAddress{{ID: 3, Email: "user2@example.com"}},
+		},
+		{
+			UID:      4,
+			expected: []*user_model.ActivatedEmailAddress{{ID: 11, Email: "user4@example.com"}},
+		},
+		{
+			UID:      11,
+			expected: []*user_model.ActivatedEmailAddress{},
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(fmt.Sprintf("User %d", testCase.UID), func(t *testing.T) {
+			emails, err := user_model.GetActivatedEmailAddresses(db.DefaultContext, testCase.UID)
+			assert.NoError(t, err)
+			assert.Equal(t, testCase.expected, emails)
+		})
+	}
+}