Address book page

[Tbaut]

Right now, users can set a name for any address they see, either for the signatories of a mutlisig, or any multisig or pure proxy address.
This is stored in local stoage, but there is no easy way to actually browse the current addresses.

We should add a dedicated page accessible from the main menu to

• see all the addresses in localstorage
• see the associated names
• edit them
• search entries by name or address (partial search)
• delete any entry
• add a new entry