This string shows up in the UI for the comment cloud backup,
which should not be confused with wallet backup and as such
it is best to avoid using the word 'backup'.
Before the item is at Tip, we don't download / upload the store,
this now is shown on screen should the user hit the 'store now'
button to make the UX clearer.
While doing a write-up I realized that an 8 byte hash is still super
overkill to isolate one transaction in a specific wallet while we also
know the block-height it is at.
This limits it to 3 bytes, which should be plenty and thereby shring the
export size quite nicely.
tomFlowee