[CoW Protocol] Known Solvers Part 2 (#1284)

* use CSV for known solvers

* attempt another copy command format

* only include CSV

* use \x instead of 0x for bytea type and rename csv to solver_names

* create table solver_names

* build view solvers from solver_names

* format string to read URL correctly

* cast address as text for replace()

* revert #1263

* delete solver names

Co-authored-by: jeff-dude <[email protected]>