[ 💻 Clarity VM ] Optimize stack pointer management

[obycode]

Currently, we are incrementing the stack pointer (a Wasm global) each time a new value needs to be pushed to the execution stack (the current function's stack frame in the linear memory). Instead, we should do a compilation pass that computes the total stack size needed for a function, and increments the stack pointer once, during the function prologue, and save the offsets for each local to use during the compilation pass.