Add full support for RUN --mount=type=cache flags

[mkesper]

RUN --mount=type=cache understands some flags the parser doesn't recognize yet:

ARG debian_version=12
FROM debian:bookworm-slim
RUN --mount=id=debian:${debian_version}-/var/cache/apt,sharing=locked,target=/var/cache/apt,type=cache \

Errors with:
Dockerfile:3:13 unexpected "id=debian:${" expecting "from=", "readonly", "readonly=", "readwrite", "readwrite=", "ro", "ro=", "rw", "rw=", "type=", source=, or target=