* Add `args` field in addition to `command`.
* Implement logic in atelet to resolve both argv from the actor template
fields and the OCI image config (`entrypoint` and `cmd` fields).
* Update demos to not hardcode command as now we honor the image
default, which makes it not necessary.
Fixes#456
Related to #292 and #119
Changes:
1. ResumeActor:
1. During `ResumeActor` we'll put the actor in CRASHED state if the
Resume failed due to any errors related to the snapshot itself, which
includes:
1. Missing or corrupted snapshot when downloading from GCS
2. Runsc command fails.
2. All other types of errors will not put the Actor in CRASHED state.
2. SuspendActor or PauseActor
1. During `SuspendActor` or `PauseActor` we'll put the actor in CRASHED
state if we cannot produce a valid snapshot, which includes:
1. cannot connect to Ateom after retries,
2. runsc command fails.
3. cannot upload the snapshot to GCS (during suspend) ; or cannot save
snapshot locally (during pause).
2. All other types of errors will not put the Actor in CRASHED state.