Add 'chunk' size setting to form, for batch-processed entities to analyze

[stefanospetrakis]

Issue Description

This is a feature allowing handling issues related to performance, by adjusting the chunk size (default value is 5) of batch analysis operations.

Impact

UX. Can be ignored (defaults to 5). Or, can be adjusted if:

1. Increasing the chunk size allows using more of the available resources
2. Decreasing the chunk size allows using less of the available resources

Security considerations

From this comment in #4

having a chunk_size setting exposed to the user does not seem like a fix to me at first glance but as a UX vulnerability, allowing the user to break the process.

This can be handled by following a permission-based approach for rendering the form element and using the submitted value.

(weak) counter-argument: The same concern can be raised for the limit property