test: feature_init: include more interruptions points

Summary:
Reorganized array according to order of logs and included 4 more interruption events:

• 'Checking all blk files are present'
• 'init message: Starting network threads'
• 'Validating signatures for all blocks'
• 'Starting HTTP server'

This is a backport of core#23782

Test Plan: ninja check-functional

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D12612