fix(task dates): leave editing mode of inline fields when task changes

Related to: CAM-2623

style(task meta): remove some commented code

impr(task history): align the user name on the right

fix(inline field): reset the edit value

Related to: CAM-2623
refactor(task): remove some obsolete code
impr(task diagram): prevent loading of diagram when tab not selected

This commit also add some CSS styling.

Related to: CAM-2652