Catch ort exception when trying to allocate key value cache

[baijumeswani]

Addresses #980

[RyanUnderhill]

The diff in github looks bigger than it really is due to the indents?

Since it looks like it's just adding the try/catch unless I'm missing something.

[baijumeswani]

Yes, the indents make it look bigger than it really is.

[f2bo]

Hi. I originally reported #980. While the updated error message is better, it doesn't identify the root cause unless you are familiar with the runtime's internals, especially when raised following a call to a higher level component. Perhaps, it would be more actionable if it made the association with the 'max_length' option.