Future commit will remove the FeeBumper class. This commit simply places
everything into a feebumper namespace, and changes the enum class name
from BumpeFeeResult to feebumper::Result.
Future PRs will completely refactor this translation unit and touch all
this code so we rename the variables to follow project stlye guidelines
in this preparation commit.
Don't use m_ prefixes for member variables since we're going to remove
the class entirely in the next commits.
Add support for setting each of these attributes on a per RPC call basis to sendtoaddress, sendmany, fundrawtransaction (already had RBF), and bumpfee (already had RBF and conf target).
No change in behavior. Get rid of specifiedConfirmTarget if/else block and
rename specifiedConfirmTarget and ignoreUserSetFee variables to
ignoreGlobalPayTxFee.
