Load Clip Plugin should handle missing frameStart/frameEnd version attribute

[TobiasPharos]

Is there an existing issue for this?

• I have searched the existing issues and added correct labels.

Description

Current Behavior

https://github.com/ynput/ayon-nuke/blob/c148e7ec47b914fbcecfd4f646ec8752537d26bc/client/ayon_nuke/plugins/load/load_clip.py#L135C1-L138C32

currently sets first and/or last to None if the version attributes frameStart or frameEnd aren't set, which then leads to an error in the following calculation, which tries to add/subtract a number to/from None.

Expected Behavior

Should fail gracefully or have a fallback

Steps To Reproduce:

Load a version without frameStart set using Load Clip.
Loading via the Ayon Loader leads to a cryptic error, loading via a workfile template will fail to resolve the corresponding placeholder.

Additional context:

No response

Relevant log output:

TypeError: unsupported operand type(s) for -=: 'NoneType' and 'int'