Add --always-allocate Flag to Reduce Branching

[bbyalcinkaya]

During symbolic execution, allocObject introduces branching for ScVals that have both small and host object representations (e.g., small/big I64s, symbols). The prover must explore both representations, leading to exponential branching (2^N branches for N arguments), which significantly impacts performance for tests with multiple such arguments.

This PR adds the --always-allocate flag to the komet prove command. When enabled, the flag forces all eligible ScVals to be allocated as host objects, eliminating the branching caused by symbolic ambiguity.

• The --always-allocate flag sets a configuration cell (<alwaysAllocate>) that modifies the behavior of allocObject.
• Only ScVal types with both small and host object representations are affected (e.g., small/big I64s, symbols). Types like void, error, and bool, which are always small, remain unaffected.
• By reducing branching, this change improves prover performance and simplifies symbolic execution.

This feature is optional, ensuring the default behavior remains unchanged unless explicitly enabled.