Update smoketest commands to replace subo create runnable

[hola-soy-milk]

I noticed that subo create runnable no longer works. @cohix am I correct in assuming it should be subo create module now?

[flaki]

So I rebased this upon #360 but somoketests will still fail, simply because we have updated the module (née "runnable") detection code from .runnable.yaml-s to .module.yaml-s, which change needs to go into subo first, then we need to update the builder Docker images because they bundle subo -- and you guessed it, the smoketest uses the Docker toolchain.

[flaki]

This last commit adds make subo/toolchaintest via ./scripts/toolchaintest.sh that is largely the same as the smoketest except it builds its own local dev images and uses them. I yoinked out these image builds from builder.mk, though they are largely the same as the builds in there so in the future we could refactor this and get rid of the duplication but for now this means that make subo/toolchaintest will build new images and test project & module creation; currently this test should be passing (it does on my machine).

[flaki]

(Please note: the tests should succeed but cleanup might fail due to root-owned build artifacts as per #342; but this is a sort of chicken & egg problem as I need the image builds and tests to work before I can get on finishing that change so this can be safely ignored for now)

[arbourd]

Closing this as we recently implemented this (and split the templates). Thanks @hola-soy-milk!