Update timing.json

Summary:
Adds a few new tests, and update the timings.
feature_bip68_sequence, p2p_feefilter and rpc_fundrawtransaction
are no longer part of the extended suite.

List of the extended tests:

• abc-p2p-compactblocks,
• abc-p2p-fullblocktest,
• feature_block,
• feature_dbcrash,
• feature_pruning,
• mining_getblocktemplate_longpoll,
• p2p_timeouts,
• wallet_backup.

Test Plan:

./test/functional/test_runner.py --extended

Reviewers: #bitcoin_abc, deadalnix, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D3918