Allow configuration of guest trace storage

## Description
Currently, we have a [fixed capacity](https://github.com/hyperlight-dev/hyperlight/blob/main/src/hyperlight_guest_tracing/src/state.rs#L52) for the `Vec` that stores the guest tracing events.
We want to allow the guest to configure the maximum space allowed to be allocated for the traces.

## Rationale
`Hyperlight` does not know the guest's memory use constraints, hence allowing a guest to configure its preference at runtime, gives flexibility to the users.

## How
One option would be to use a weak symbol in the guest, for which `hyperlight` provides a `default` implementation.