Add option to flush streams when memory threshold reached

[Tolsto]

Problem

The memory consumption of a job is often not foreseeable,
especially when the amount of data is highly inconsistent.
It would either require to set the max batch size low enough
to accommodate every possible load pattern, or to over-provision
memory.

Proposed changes

This change adds a safeguard against OOM events by flushing all
streams as soon as the memory consumption reaches a certain threshold.

Types of changes

What types of changes does your code introduce to PipelineWise?
Put an x in the boxes that apply

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

• Description above provides context of the change
• I have added tests that prove my fix is effective or that my feature works
• Unit tests for changes (not needed for documentation changes)
• CI checks pass with my changes
• Bumping version in setup.py is an individual PR and not mixed with feature or bugfix PRs
• Commit message/PR title starts with [AP-NNNN] (if applicable. AP-NNNN = JIRA ID)
• Branch name starts with AP-NNN (if applicable. AP-NNN = JIRA ID)
• Commits follow "How to write a good git commit message"
• Relevant documentation is updated including usage instructions

[devon-seitz-cirrusmd]

This feature would be very helpful for me too