Add errors.Ignore()
Created by: camdencheek
This adds the new helper function Ignore
to our errors
package. This
allows us to ignore errors based on a given predicate function in a way
that takes into account aggregated errors in MultiError. It recursively
unwraps to multierrors an filters out all child errors that match the
predicate.
Test plan
Solid unit tests were added as part of this PR.