Correct error handling to not use BaseException

[Overlord360]

Splits off #229 as we don't have push access to Riley's branch / fork.

I've added a top level FixateError as per Clint's recommendation in #229

[aedwards-ampcontrol]

@daniel-montanari and another one for your review please.

[daniel-montanari]

@Overlord360 do the excepts for BaseException in main, sequencer.py and common,py need to be changed?
Looking over the previous PR an skimming over the code it looks ok to me, but wanted to make sure someone else has also checked.

Has anyone done any checks with atgrep to make sure there aren't scripts that will break unexpectedly?

[Overlord360]

@Overlord360 do the excepts for BaseException in main, sequencer.py and common,py need to be changed? Looking over the previous PR an skimming over the code it looks ok to me, but wanted to make sure someone else has also checked.

Has anyone done any checks with atgrep to make sure there aren't scripts that will break unexpectedly?

@daniel-montanari
Since Exception inherits from BaseException the sequencer.py BaseExcecption excepts will work just as they have until now.

As for other test scripts there appear to be four places where BaseException are used in test scripts.

The three uses in the ELV jig use the retry_exceptions variable inherited from the TestClass class in fixate which has been deprecated for 8 years

In the Rockstarter protection board test script it's used to create a custom exception. This should be changed to inherit from Exception instead of BaseException.
That being said. This will still act the same as the exception handling in the sequencer has not been changed.

[daniel-montanari]

Looks good just add to release notes please

[Overlord360]

Looks good just add to release notes please

@daniel-montanari Done!