[BRANDING] Update nodeinfo branding

- Change the values for the nodeinfo API, to use branded values.
- Resolves https://codeberg.org/forgejo/forgejo/issues/257

(cherry picked from commit 4608c57688)
(cherry picked from commit e837e8a529)
(cherry picked from commit 6601328d3c)
(cherry picked from commit c6be21d487)
(cherry picked from commit 5adc6ffee2)
(cherry picked from commit 2ff8d166ac)

tests/integration/api_nodeinfo_test.go

@@ -32,7 +32,7 @@ func TestNodeinfo(t *testing.T) {
 		var nodeinfo api.NodeInfo
 		DecodeJSON(t, resp, &nodeinfo)
 		assert.True(t, nodeinfo.OpenRegistrations)
-		assert.Equal(t, "gitea", nodeinfo.Software.Name)
+		assert.Equal(t, "forgejo", nodeinfo.Software.Name)
 		assert.Equal(t, 24, nodeinfo.Usage.Users.Total)
 		assert.Equal(t, 18, nodeinfo.Usage.LocalPosts)
 		assert.Equal(t, 2, nodeinfo.Usage.LocalComments)