[Eva] Generalize the callstack type to include global initialization

src/dune

src/kernel_services/abstract_interp/eva_types.ml

src/kernel_services/abstract_interp/eva_types.mli

src/plugins/eva/Eva.mli

src/plugins/eva/api/values_request.ml

src/plugins/eva/engine/compute_functions.ml

src/plugins/eva/engine/initialization.ml

src/plugins/eva/types/callstack.mli

src/plugins/eva/utils/eva_utils.ml

src/plugins/eva/utils/results.ml