Show the update status of services

[mhaamann]

Current Portainer version: 1.19.1

Problem:
Docker swarm is sometimes a bit flaky in rolling updates and sometimes service updates simply takes a long time because many containers needs to be updated.
When looking at the Portainer service overview there is no way of checking the UpdateStatus for services (updating, rolling back, failed, completed).

Solution:
Add a small identifier that shows the state of the update.
Example:
https://www.dropbox.com/s/p4rlyylwsptarfp/Screenshot%202018-08-10%2013.36.07.png?dl=0
Green: Update completed.
Blue: Update in progress.
Red: Failed
Orange?: Rolling back

It seems that all the data needed is already in the endpoints. The change would be a simple UI update.

[mhaamann]

@deviantony I might have time to develop this feature. Do you have any comments on the look and feel?

[deviantony]

@mhaamann We could add a label to the "Last update" column:

• "complete" green label when update is OK.
• "in-progress" yellow label when update is in progress
• "failed": red label when update is KO
• "rolling-back" yellow label when update is in rollback state

Thoughts @ncresswell ?

[ghost]

related to #919