Sometimes wrong actions and references are displayed in menu

[teosarca]

Test case:

• open a document (e.g. a particular sales order)
• press the menu to trigger the document actions & references loading
• go to another document or grid view
• press the menu to see the actions and references
• for a while you will see the old ones (from previous document)

Usually this is obvious on slow connections where the document actions and references endpoints have delays.

How it shall be: when user presses Menu button

• clear document actions and references
• display an indicator (text or some other rotating shit) that the documents are currently loading
• populate when you got them

[damianprzygodzki]

@cadavre
TODO: indicator for document actions & referenced documents in subheader

[teosarca]

And btw, i think we shall have exactly the same approach on ALL OTHER things which are lazy/just in time loaded.

[damianprzygodzki]

Definetely we should provide one the same loader for all of lazy elements.

[teosarca]

About lazy loading, i've created a new issue to gather ideas: #130