d099b9c195 Remove wildcard from prelude import (Jamil Lambert, PhD)
Pull request description:
This patch replaces `prelude::*` wildcard imports with the types actually used. In a couple of cases `DisplayHex` was previously imported by the wildcard but was only used in the test module, an additional import was added to the test module instead of at the top where it causes an unused import warning.
Close: #2875
ACKs for top commit:
Kixunil:
ACK d099b9c195
tcharding:
ACK d099b9c195
Tree-SHA512: d59dfac0961d2649d509039a11c1b5574d81d05fef567a624cf15be2f587de796ea960ba5a08bef788199331c2f790fb06f7b393182538c7d8b1891ded119efc