Include message-simple-data in the MessageSimple height

[MartinCupela]

Problem

The str-chat__message-data str-chat__message-simple-data element (child of MessageSimple) has position:absolute and so is not counted towards the margin-bottom of the last message in the message group. That makes it more difficult to control spacing below the last message in the message group.

Proposed solution

To make it easier for the integrators to control spacing between the messages - e.g. to have equal spacing between the messages without having to calculate the height - the message data component should have position: static. That will have impact on the position of Avatar, that will be lowered down to the level of message-data. The Avatar can be positioned by adding padding or margin-bottom to its wrapper.

Ref to the problem:

stream-chat-css/src/styles/Message.scss

Line 888 in 6c0aff9

position: absolute;

Also the data container cannot be a sibling of the message text bubble if it has position: static. Otherwise the message actions button will be pushed to the center of the screen.