[web] provide details in error notification

[exalate-issue-sync]

Description

User Stories

• As owncloud support I want to retrive easily technical info from users so that I can understand and solve the users problem.

Value

• lower internal efforts
• improve stability of ocis

Acceptance Criteria

• if an error occurs, the error message can define if it is self-closing or not
• all error messages are not self-closing
• the error details are shown on all errors that are currently displayed in the ui
• the error message contains
  • Headline
  • teaser text (if given - this should already work as it is)
  • link "show details"
    • detailed text
    • Copy to clipboard button

[~tbaader]please add scribbles

Definition of ready

[ ] everybody needs to understand the value written in the user story
[ ] acceptance criteria has to be defined
[ ] all dependencies of the user story need to be identified
[ ] feature should be seen from an end user perspective
[ ] user story has to be estimated
[ ] story points need to be less then 20

Definition of done

• Functional requirements
  [ ] functionality described in the user story works
  [ ] acceptance criteria are fulfilled
• Quality
  [ ] code review happened
  [ ] CI is green
  [ ] critical code received unit tests by the developer
  [ ] automated tests passed (if automated tests are not available, this test needs to be created and passed
• Non-functional requirements
  [ ] no sonar cloud issues

[exalate-issue-sync]

Jan Ackermann commented: technical suggestion : add showErrorMessage function, similar to showMessage

Reason: easy to identify, extendable interface