move jquery-datetimepicker to npm/webpack (#10713)

- update to latest version and move to npm
- adapt for api changes and css class rename
- add specificity to arc-green rules as dependency css now loads later
- use imports-loader to make it load correctly
- fix some wrong paths in librejs

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

web_src/less/themes/theme-arc-green.less

@@ -1345,12 +1345,12 @@ a.ui.labels .label:hover {
     }
 }
 
-.xdsoft_datetimepicker {
+body .xdsoft_datetimepicker {
     background: #2a2e39;
     border: 1px solid #4c505c;
     color: #9e9e9e;
 
-    .xdsoft_mounthpicker {
+    .xdsoft_monthpicker {
         height: 36px;
         background: #464c5d;
         margin: -2px -8px 2px;
@@ -1416,7 +1416,6 @@ a.ui.labels .label:hover {
             background: #a0cc75;
             color: #000000;
         }
-
     }
 }