Paragraph integration for rich text editor (#10008)

* integrates paragraph refactor in rich text editor
* minor CSS changes to accomodate this
* bumps rich text editor version to 0.22.0

res/css/views/rooms/_EventTile.pcss

@@ -639,8 +639,8 @@ $left-gutter: 64px;
             list-style-type: disc;
         }
 
-        /* Remove top and bottom margin for better consecutive list display */
-        > :is(ol, ul) {
+        /* Remove top and bottom margin for better display in rich text editor output */
+        :is(p, ol, ul) {
             margin-top: 0;
             margin-bottom: 0;
         }

res/css/views/rooms/wysiwyg_composer/components/_Editor.pcss

@@ -37,6 +37,20 @@ limitations under the License.
             user-select: all;
         }
 
+        // we always have a <br/> tag at the end of the html, we need it to be present at first then hide it as soon as
+        // we have any other elements
+        br:not(:only-child) {
+            display: none;
+        }
+
+        p {
+            margin-top: 0;
+            margin-bottom: 0;
+            // this may seem redundant, but we need to handle zero content formatting tags, which occur when we split a
+            // formatting tag into paragraphs
+            min-height: $font-22px;
+        }
+
         ul,
         ol {
             margin-top: 0;
@@ -56,12 +70,6 @@ limitations under the License.
             margin-inline-end: 0;
         }
 
-        // model output always includes a linebreak but we do not want the user
-        // to see it when writing input in lists
-        :is(ol, ul, pre, blockquote) + br:last-of-type {
-            display: none;
-        }
-
         > pre {
             font-size: $font-15px;
             line-height: $font-24px;