Revert "[backport#15639] bitcoin-wallet tool: Drop libbitcoin_server.a dependency"

Summary:
This reverts commit a7a55fb3ac4f7f8b6dd97fa51b4f2cd21a871022, turns out there's still work to be done before that dependency can be dropped

it also:

• removes redundant target_link_libraries calls related to the wallet <-> server circular dependency
• removes a libevent dependency from wallet since the only function that needed it was moved to src/util/url.cpp
• added an explicit libevent dependency to util, and moved the code that finds libevent to account for that

Depends on D6256

Test Plan:

../configure
make

cmake .. -GNinja
ninja

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Subscribers: deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6269