Bump version for 0.14.5 release

Summary:
Bump version to 0.14.5, and put release notes for 0.14.4 in

doc/release-notes/

Test Plan: Read release notes to check they make sense

Reviewers: freetrader, deadalnix, #bitcoin_abc, kyuupichan

Reviewed By: freetrader, #bitcoin_abc, kyuupichan

Differential Revision: https://reviews.bitcoinabc.org/D356