Request to add an option to enable assert + message support in analysis server

[sethladd]

Following on the work from #24217

We'd love a way for a user to opt-in to support for assert + message in Analysis server.

Thanks!

[bwilkerson]

One possible approach for this would be to add the flag via the .analysis_options file.

[sethladd]

I'm a fan.

[stereotype441]

Note: FixProcessor._inferUndefinedExpressionType will need to be modified so that fixes like "create local variable" will infer the correct type for the assertion expression.