Allow for mark read and mark unread through the side button, and
change its style according to spec in the ticket.
Bug: T126214
Change-Id: I78a93c0545bbe2d7c11a0c62557cd2e97e9d3866
The items should resemble the popup items, but the styles clashed
with the popup's cross-wiki notification item, so the image size
was smaller and the border was incomplete.
Bug: T136572
Change-Id: I3c3f825d469ccee1e711da21f627eeb9491e9480
* Use `margin: A` with `padding: B` rather than `padding: calc(A + B)`.
* Remove a `display: inline-block` which necessitated `width: 100%`.
I think this results in the same rendering, but please test carefully,
as I didn't check it for all the possible notifications.
(There is one more calc() in mw.echo.badge.less that can't be avoided.)
Bug: T135936
Change-Id: Ic01f16c8469c3b9d45d2885108ec6260e967731a
Changing the way Echo's front-end architecture works to work with
model-view-controller methodology.
Change-Id: I97862402c41bc04dd41cd08d79f19ff677340249
