use factory method design pattern instead of `init`'ing "modules" directly

- by running `init` directly, we may increase churn and certain inconsistencies in the source (see below)
- we could initialize modules by having something like a `load_module` function that takes a name and a "function pointer" for "loading" and "unloading"

pros:
- we would avoid inconsistencies in where the conditions for the initialization of a module take place (https://github.com/hermit-os/kernel/pull/1970)
- we could give modules a "name" and modify the macros used so that logs/kernel messages use said name, achieving a more "linux-like dmesg"-type of structure (https://github.com/hermit-os/kernel/pull/1974)
- i.e. custom macros, similarly to `pr_debug` or `pr_info` in the linux kernel
- we could standardize "loading" and "unloading" modules similarly to the linux kernel
- an "enforced structure" wouldn't necessarily compromise flexibility, as we already do things like this anyway.