EPIC: Deprecating, removing and making functionalities optional features

[milenkovicm]

As per our discussion in #1066 I'm opening this epic to break down PR #1066 to set of smaller chunks.

• [x] #1069 - datafusion python is the main effort, we should focus making it run on ballista
• [x] #1071- this can be contrib project
• [x] #1074 - ci works without it, could not relate content to anything in the repo
• [x] #1070 - never finalized, dangling code
• [x] #1076- this can be a contrib project, we could cover it with pluggable scheduler strategies
• [x] #1073 - library too old, there are newer library to be used
• [x] #1072 - can be a contrib project
• [x] #1079
• [x] #1084
• [x] #1077 - only memory store remains, we may want to take different approach, like checkpointing or similar
• [x] #1078
• [x] #1075
• [x] #1080
• [x] #1085
• [ ] enable all optional features in tests
• [x] #1089

For could be contrib functionalities I suggest just to remove them at this point, who ever needs them can make contrib project from them

[milenkovicm]

@andygrove the other few PR will be pushed once we finish with current backlog, they may introduce merge conflicts