RSDK-9174: add app wrappers

[purplenicole730]

Adding all the app wrappers.

Notes:

• I did add multiple files to try and split up the file a little between the wrappers and types as there are just so many. I can easily consolidate app_proto_conversions.go into app_client.go if preferred.
• There are also some shadow types that are used in ML Training in registry_proto_conversions.go. I kept this here since ML Training will be using this too, so I'll probably use this file and rename it as the ML Training client. Anything ML Training does not use when we introduce the ML Training wrappers will probably go back into app_proto_conversions.go.
• Talking to @benjirewis and @jckras, we came to the conclusion that for TailRobotPartLogs, we can give the stream object itself to the user so that the user does what they want with it, whether they want to make it a channel or not. This seems to be common practice in Go.

[benjirewis]

Looking awesome; this is a large amount of work thanks so much! Two comments: I think we should use a different strategy for "optional" fields, and I have some comments about your streaming code I can relay offline.