Generalize logic to get trigger options

[ejizba]

I always hated manually specifying these trigger properties, but I never had a cleaner way to do it and keep TypeScript happy (without resorting to any types everywhere). Well, I think I figured one out. Here's the basic idea:

// Example options
const options = { handler: () => 'hello world', connection: 'storage_APPSETTING', queueName: 'testQueue' };

// Before
const handler = options.handler;
const triggerOptions = { options.connection, options.queueName };

// After
const { handler, ...triggerOptions } = options;

I had to work some magic to combine it into one shared function, but got it figured out for everything except the cosmos one. Something about the union type CosmosDBv3TriggerOptions | CosmosDBv4TriggerOptions is throwing TypeScript off, but functionally it should be fine and I still prefer this overall.