[cmake] Double the functional test timeout when a sanitizer is enabled

Summary: The sanitizers can have a lot of overhead, especially TSAN. Some tests have their RPC timeout bumped already but this does not apply to all the timeouts, like wait_until timeouts which occasionnaly causes false positives on CI that can be reproduced easily enough on slow machines.

Test Plan:
With and without tsan:

ninja check-functional

Reviewers: #bitcoin_abc, sdulfari

Reviewed By: #bitcoin_abc, sdulfari

Differential Revision: https://reviews.bitcoinabc.org/D11776