[Bug]: adf-account-management StateMachine fails if first 30 characters of account name are similar.

### Is there an existing issue for this?

- [X] I have searched the existing issues

### Describe the bug

When you create multiple accounts in a single file the StateMachine fails to start cause stepfunctions states that it has already been started:

[ERROR] ExecutionAlreadyExists: An error occurred (ExecutionAlreadyExists) when calling the StartExecution operation: Execution Already Exists: 'arn:aws:states:us-east-1:xxxxxxxxxxx:execution:adf-account-management:LongClientName___Business_Names__-29a4174a-4ce7-4597-bc58-89fda1121172-96ac41b3da60'
Traceback (most recent call last):
File "/var/task/process_account_files.py", line 206, in lambda_handler
start_executions(
File "/var/task/process_account_files.py", line 179, in start_executions
sfn_client.start_execution(
File "/var/task/botocore/client.py", line 565, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/var/task/aws_xray_sdk/ext/botocore/patch.py", line 38, in _xray_traced_botocore
return xray_recorder.record_subsegment(
File "/var/task/aws_xray_sdk/core/recorder.py", line 456, in record_subsegment
return_value = wrapped(*args, **kwargs)
File "/var/task/botocore/client.py", line 1021, in _make_api_call
raise error_class(parsed_response, operation_name)

So in case the accounts follow a naming standard like:
LongClientName - BusinessName - Development/Production etc

The 30 selected first letters + id from process_account_files.py sends the exact same ID for both accounts into step functions.

### Expected Behavior

Should run for each account in the account file, with zero regard to the naming being similar.

### Current Behavior

ERROR] ExecutionAlreadyExists: An error occurred (ExecutionAlreadyExists) when calling the StartExecution operation: Execution Already Exists: 'arn:aws:states:us-east-1:xxxxxxxxxxx:execution:adf-account-management:LongClientName___Business_Names__-29a4174a-4ce7-4597-bc58-89fda1121172-96ac41b3da60'

The execution of the file stops - it will not try to run the state machines for accounts below the first failure either.

### Steps To Reproduce

Add two new accounts into the account file, with first characters being the same.

### Possible Solution

Add a short random string in front of the account name, instead of behind in step function trigger.

### Additional Information/Context

_No response_

### ADF Version

4.0.0

### Contributing a fix?

- [ ] Yes, I am working on a fix to resolve this issue

Start in process_account_files.py, especially start_executions around line 179 and lambda_handler around line 206, then reproduce with two accounts whose names share the same first characters. Check how execution names are built and run the account-file flow. Done means each account starts its own StateMachine execution and later accounts still run after the first one.

Written by the indexing model from the issue text.