Set common width, white-space, and display values to MessageTimestamp (#8818)

* Add mx_MessageTimestamp to mx_PinnedEventTile_timestamp

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Apply display: block globally to enable the width declaration

- Unset display and width value of timestamp on pinned messages card

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Apply nowrap globally

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* MessageTimestamp on ThreadsList - Remove width setting and add font-size setting

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Remove redundant font-size declaration from Threadview

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Fix timestamp position of timestamp on ThreadView in IRC layout

- GroupLayout is modern layout, not IRC layout

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Remove redundant font-size declaration from IRC layout

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Remove redundant color setting from timestamp on file panel

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Cancel the default width to set a gap between the event tile line

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

* Apply user-select: none globally

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

src/components/views/rooms/PinnedEventTile.tsx

@@ -144,7 +144,7 @@ export default class PinnedEventTile extends React.Component<IProps> {
             </div>
 
             <div className="mx_PinnedEventTile_footer">
-                <span className="mx_PinnedEventTile_timestamp">
+                <span className="mx_MessageTimestamp mx_PinnedEventTile_timestamp">
                     { formatDate(new Date(this.props.event.getTs())) }
                 </span>