Worker config updates to make path to jave.exe configurable

[pragnagopa]

• Added support to provide worker description profiles
• Added support to override default worker process path by specifying app setting languageWorkers:language:defaultExecutablePath

Fixes #3187, Fixes #3048

[pragnagopa]

Sample worker.config.json with AppServiceEnvironment profile

{
    "Description":{
        "Language":"java",
        "Extension":".jar",
        "DefaultExecutablePath":"java",
        "DefaultWorkerPath":"azure-functions-java-worker.jar",
        "Arguments" : ["-jar"]
    },
	"profiles": {
		"AppServiceEnvironment": {
			"DefaultExecutablePath": "../../zulu8.23.0.3-jdk8.0.144-win_x64/bin/java"
		}
	}
}

• When running in Azure, if AppServiceEnvironment profile is provided this overwrites defaualt description.
• Users can specify AppSetting languageWorkers:language:defaultExecutablePath to override worker process path

PR Azure/azure-functions-java-worker#151 updates worker.config.json for java worker

[pragnagopa]

Updated to Java worker.

[fabiocav]

Wondering if it would save us all some time (and avoid migration issues) if this was targeting the hosting branch instead. We're about to merge that in. What do you think?

@brettsam , thoughts?

[brettsam]

Yes! and in fact, there's some issues with worker config today in hosting (some values aren't getting applied like I'd expect). It'd be good to get it all reconciled at once.

[fabiocav]

Couple of nit comments

[fabiocav]

Should this > -1?

[fabiocav]

Should this be something like WorkerProfileNameAppServiceEnvironment ?

[fabiocav]

@brettsam , just had a quick chat with @pragnagopa . Since we haven't changed that model for language workers in the hosting branch yet, I don't think what she is adding expands what we'd have to migrate too much, so it should be fine to go into dev. Thoughts?

[pragnagopa]

Right. @brettsam - I will go ahead and merge this into dev and work with you and @fabiocav for specific changes we need to make to consume the new config model.