Merge bitcoin/bitcoin#23782: test: include two more interruptions points

618f4d2 test: re-organized array according to order of logs and included 2 more interruption events (seaona)
71115a5 test: include two more interruptions points (seaona)

Pull request description:

  This PR aims to introduce 2 more interruption points in the process of initialization, in order to make the` feature_init `testcase more complete. These are the following:

  -` Checking all blk files are present`
  -` init message: Starting network threads`

  It is a small improvement for increasing the coverage of potential interruptions, and making sure that the node can restart successfully after these interruptions.

ACKs for top commit:
  jamesob:
    ACK bitcoin/bitcoin@618f4d2, pending CI
  jarolrod:
    ACK 618f4d2

Tree-SHA512: 9d709734e298e955709094bb97478ca7f18859874f1ba026f7c9014d87205aea63f6cf2093ebee600eaf82d3245adb11e77fae24a1ae48b69efefd57f3def921

test/functional/feature_init.py

@@ -57,19 +57,23 @@ def check_clean_start():
             assert_equal(200, node.getblockcount())
 
         lines_to_terminate_after = [
+            'Validating signatures for all blocks',
             'scheduler thread start',
+            'Starting HTTP server',
             'Loading P2P addresses',
             'Loading banlist',
             'Loading block index',
             'Switching active chainstate',
+            'Checking all blk files are present',
             'Loaded best chain:',
             'init message: Verifying blocks',
+            'init message: Starting network threads',
+            'net thread start',
+            'addcon thread start',
             'loadblk thread start',
             # TODO: reenable - see above TODO
             # 'txindex thread start',
-            'net thread start',
-            'addcon thread start',
-            'msghand thread start',
+            'msghand thread start'
         ]
         if self.is_wallet_compiled():
             lines_to_terminate_after.append('Verifying wallet')