* Move api/filesys to kyaml/filesys
* Add deprecated version of api/filesys with aliases to new code
* Use new kyaml/filesys package and update dependencies
* Migrate to kyaml/filesys and update dependencies
* Skip tests that break on Windows
* Make fsNode handle correctly consecutive reads and writes
* Check for directories in ReadFile and add some error checks
* Update comment
* Improved docs and added better test
* Move test into its own file protected by built constraint
* Use manual test since iotest.TestReader is only available in Go 1.16
The apimachinery code path, in its final marshalling
for output, calls Marshall
https://github.com/go-yaml/yaml/blob/v2/yaml.go#L199
This code path (via apimachinery Unstructured types)
has no JSON schema tags
https://yaml.org/spec/1.2/spec.html#id2803311
so it adds quotes to values that smell like
booleans and ints (e.g. `false` becomes `"false"`).
The kyaml code path, OTOH, uses such tags,
so generally does not quote ints and booleans.
This PR isolates this difference in behavior to
one set of tests (using data fields in configmaps
in api/krusty/configmaps_test.go) so that
they don't confuse other tests that cover
completely different behaviors.
