Combine cart and transaction summary into one page

Collapse transaction summary and cart editing into just one page: Transaction Summary is probably ok name still. Replace json view at bottom with the cart editing interface. If there is some desire to see the ugly raw json, user can save to a file.

Reordering buttons should move focus to keep on reordered operation. This allows user to move a particular operation to a particular spot (this is also consistent with how similar UIs work in other programs).

Note: when operations are removed or edited, transaction hash will need to be recalculated.

When user enters this page, the transaction will include as many "Useful" key roles (e.g. alpha@active) that wallet plans to sign the transaction with. Need to decide how to display this set of keys (later will be editable too).

Primary function keys (fkeys):

• F1: Broadcast (this also actually signs with visually specified set of keys that are available) (available when wallet is online)
• F2: Save (this also signs with any available private keys and stores meta-data about other keys still needed as part of save process). (available online and offline)

Secondary Fkeys (maybe not needed): possibly some of the editing keys from edit cart page, maybe not needed if tab interface is simple enough. Currently those extra keys are: Remove/Next/Prev/Clear_all

TODO: number the sub-issues here to be sure completed.

Operation page

On operations page, stay on same operation page after operation is added to the cart, don't go back to main page of operations.