ArgsEscaped according to Docker docs should only be set in Windows
environments: https://docs.docker.com/engine/api/v1.30/
It was causing integration test to fail with following message:
```
FAIL: TestRun/test_Dockerfile_test_metadata (8.48s)
"Diff": {
"Adds": [
"ArgsEscaped: true"
],
"Dels": [
"ArgsEscaped: false"
]
```
However docker 18.xx returns ArgsEscaped: true
whereas docker 19.xx returns ArgsEscaped: false
Hence this patch also adds the docker version check to the integration
to ignore ArgsEscaped being different when 18.xx is used.
* Rework cache key generation a bit.
Cache keys are now based on the previous commands, rather than the previous state
of the filesystem.
* Refactor command interface a bit, only cache the context for commands that use it.
CacheCommand returns true if the command should be cached. Currently,
it's only true for RUN but can be added to ADD/COPY later on (these are
different since the contents of files for ADD/COPY need to be included
in the cache key generation).
I also changed CreatedBy to String so that we can log each command
before cache extraction or regular execution takes place.
* adding metadata tests back to integration tests and fixing resulting bugs
* fix onbuild and default env
* removing old test files
* adding the ArgsEscaped boolean on CMD commands
* fix onbuild test
* ignore failing test until container-diff is fixed
* code comments
* adding todo to remove uncomment failing test
* Vendor changes for go-containerregistry switch.
* Manual changes for go-containerregistry switch.
The biggest change is refactoring the tarball unpacking.
* Pull more of container-diff out.
* More vendor removals.
* More unit tests.