* core/types: make Signer derive address instead of public key
There are two reasons to do this now: The upcoming ethclient signer
doesn't know the public key, just the address. EIP 208 will introduce a
new signer which derives the 'entry point' address for transactions with
zero signature. The entry point has no public key.
Other changes to the interface ease the path make to moving signature
crypto out of core/types later.
* ethclient, mobile: add TransactionSender
The new method can get the right signer without any crypto, and without
knowledge of the signature scheme that was used when the transaction was
included.
* mobile: don't retain transient []byte in CallMsg.SetData
Go mobile doesn't copy []byte parameters, for performance and to allow
writes to the byte array be reflected in the native byte array.
Unfortunately, that means []byte arguments are only valid during the
call it is being passed into.
CallMsg.SetData retains such a byte array. Copy it instead
Fixes#14675
* mobile: copy all []byte arguments from gomobile
To avoid subtle errors when accidentially retaining an otherwise
transient byte slice coming from gomobile, copy all byte slices before
use.
* mobile: replace copySlice with common.CopyBytes
* build: modify the iOS namespace to iGeth (gomobile limitation)
* mobile: assign names to return types for ObjC wrapper
* mobile: use more expanded names for iOS/Swift API
