Allow dynamic configuration of maximum attribute collection size

[loewenheim]

Eventually we want to make the maximum total size of attributes configurable at runtime, probably via the project config. I can see two ways to accomplish this:

1. Pass the size into the EAP trimming processor as a parameter. This works but is pretty inelegant (why is the size of this one particular datum a property of the processor and not the value, like in all other cases)?
2. Extend the functionality for dynamic computation of max_bytes we're adding in feat: Add dynamic max_bytes/max_chars definition #5500: we could make the function that's used in the computation take a "context" parameter in addition to the processing state which would include the project config (a suitable type may already exist, else we'd have to define it).

[linear]

RELAY-191