[Data Engine]: Add Spot instances support for Standalone Spark cluster

[viravit]

As a user I want to use spot functionality during Standalone Spark cluster creation so that I can reduce financial charges on AWS/GCP/MS Azure.

Acceptance criteria:

1. It should be check box for spot instance on Standalone Spark cluster creation popup
2. Check box for Low spot instance should be checked off by default
3. If user unchecks check box for spot instance and hits 'Create' button a Standalone Spark cluster will be created without spot price
4. If user checks off check box for spot instance and hits 'Create' button a Standalone Spark cluster will be created with spot price