Added assertoor testnet testing tool.

There are currently 6 tests included:
* Check for chain stability (finalizing, high voting consensus, no
reorgs)
* Check if all clients propose a block
* Validator Lifecycle Test
Test for the whole validator lifecycle, includes Deposits, BLSChanges,
Exits & Slashings
This Test takes up to 2 days to run through due to deposit delays &
queues.
* Normal Transaction Test
Test if normal EOA transactions (type 0/2) are processed by all client
pairs (inclusion & submission)
* Blob Transaction Test
Test if blob transactions (type 3) are processed by all client pairs
(inclusion & submission)
* All-Opcodes Transaction Test
  Generates & submits a transaction that triggers every EVM opcode once.
  Checks if the transaction succeeds and no client forks off

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Co-authored-by: Barnabas Busa <busa.barnabas@gmail.com>