Restore file content changed

[pinussilvestrus]

• restores the missing file content changed notification
• rename App.js#tabHistory -> App.js#navigationHistory
• refactor tab updating workarounds

Closes #970

[pinussilvestrus]

Bug detected: When on XML-tab and agreeing the reloading, the changes did not affect. That might be caused by BpmnEditor#checkImport is not triggered again.

Fixed with last commit.

[nikku]

We need to properly integrate the tab updating with the state management as sketched in 4335ce0.

Please update your implementation as discussed.

[nikku]

Rebased on latest next branch.

[pinussilvestrus]

Updated the implementation to fit with the wanted state management handling. For this there is a new method called updateTab(tab, newAttrs) which allows to update tab properties properly. It manage replacing the giving tab with a new tab + the new attributes.

I also renamed the label of the tabHistory to navigationHistory in the App.js component to indicate what this history-list is supposed to do: Saving which tabs were navigated to and when they were visited.

Now there are a couple of things to do:

• The bug in the xml editor appears again (see previous Restore file content changed #1005 (comment)). This is caused by the broken dirty state handling Renderer crashes when switching from XML editor to DMN table editor #1023. A overall refactoring of this will be needed.
• Find out if there are tab-update procedures which works with workarounds. Try to refactor them with the new updateTab method to make the architecture more robust and avoid workarounds.

When the second task is done I will give this PR to review again.

[philippfromme]

I think the replacing of old namespaces one of the things that currently do not properly integrate with tab updating.

[pinussilvestrus]

@philippfromme Indeed, this was also the first occurrence I was thinking about 👍

Another procedure would be the updating of an empty tab with the initial file contents in App.js#openEmptyFile. #1036 is kind of blocking it. #1037 is go to fix this.

[pinussilvestrus]

@nikku all changes should be adressed now!

[nikku]

👍