Add default properties to link buttons and remove redundant settings (#8151)

* Add font-size: inherit to link button

Remove redundant font-size settings

_FeedbackDialog.scss
_GenericFeatureFeedbackDialog.scss
_Login.scss
_NewRoomIntro.scss
_NotificationSettingsTab.scss
_PinnedEventTile.scss
_PreferencesUserSettingsTab.scss
_SpaceCreateMenu.scss
_ToastContainer.scss
_UserMenu.scss

Specify font-size
- _ProfileSettings.scss
- _SpaceBasicSettings.scss
- _SpaceSettingsDialog.scss

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

* Add line-height: inherit to link button

Remove redundant setting
- _GenericFeatureFeedbackDialog.scss
- _PinnedEventTile.scss
- _SpaceCreateMenu.scss

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

* Add font-weight: normal to link button

Remove redundant setting
- _SpotlightDialog.scss
- _UserMenu.scss

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

* Dedupe _link and _link_inline

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

* Set inline to "link_inline"

Treat the button as its name indicates.
For elements that should not be inlined, "link" should be used.

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

res/css/structures/_UserMenu.scss

@@ -147,11 +147,6 @@ limitations under the License.
                     margin-top: 8px;
                 }
             }
-
-            .mx_AccessibleButton_kind_link {
-                font-weight: normal;
-                font-size: inherit;
-            }
         }
     }