enhance(webhook): add select all and deselect all buttons for custom events (#35980)

Adds `Select All` and `Deselect All` buttons to the custom events
section of the webhook form. This is useful when you need all events but
one.

- The buttons toggle every event checkbox and keep the unsaved-changes
prompt working
- Fix the "Trigger On" radio spacing by removing a leftover Fomantic
checkbox margin

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

web_src/css/modules/checkbox.css

@@ -88,10 +88,6 @@ input[type="checkbox"]:indeterminate::before {
 .ui.checkbox label {
   position: relative;
   display: block;
-}
-
-.ui.checkbox label,
-.ui.radio.checkbox label {
   margin-left: 20px;
 }
 
@@ -107,10 +103,6 @@ input[type="checkbox"]:indeterminate::before {
   pointer-events: none;
 }
 
-.ui.radio.checkbox {
-  min-height: var(--checkbox-size);
-}
-
 /* "switch" styled checkbox */
 
 .ui.toggle.checkbox {

web_src/css/modules/form.css

@@ -114,10 +114,6 @@ textarea:focus,
   vertical-align: top;
 }
 
-.ui.ui.form .field .fields .field:not(:only-child) .ui.checkbox {
-  margin-top: 0.6em;
-}
-
 .ui.form .field > .selection.dropdown {
   min-width: 14em; /* matches the default min width */
   width: 100%;
@@ -255,9 +251,6 @@ textarea:focus,
   padding-left: 0.5em;
   padding-right: 0.5em;
 }
-.ui.form .fields > .field:first-child {
-  border-left: none;
-}
 
 @media only screen and (max-width: 767.98px) {
   .ui.form .fields {

web_src/css/repo.css

@@ -952,16 +952,6 @@
   font-style: italic;
 }
 
-.repository.settings.webhook .events .column {
-  padding-bottom: 0;
-}
-
-.repository.settings.webhook .events .help {
-  font-size: 13px;
-  margin-left: 26px;
-  padding-top: 0;
-}
-
 .repository .repository-summary {
   box-shadow: none;
 }