Consider using different uint types (e.g., u8,u16 or u32) instead of usize

[aarkue]

Currently, event/object indices as well as variables and their bindings and so on are all represented as usize.
However, for most if not all realistic use cases a smaller representation would already suffice and would allow for constructing a large number of bindings.

It would be interesting to investigate if this could make sense using the following steps:

• Abstract the underlying datatype as a generic type parameter (for event/object indices and for variables seperately.
• Handle these generics in all execution functions, check how to best handle them in typescript type conversions etc.
• Evaluate if the memory usage is observably different for simple and complex queries/constraints
• Evaluate if the execution is observably different for simple and complex queries/constraints