Automatic merge from submit-queue
Escape special characters in jsonpath field names.
There may be a better way to do this, but this seemed like the simplest possible version.
Example: `{.items[*].metadata.labels.kubernetes\.io/hostname}`
[Resolves#31984]
It is common in constrained circumstances to prefer an empty string
result from JSONPath templates for missing keys over an error. Several
other implementations provide this (the canonical JS and PHP, as well as
the Java implementation). This also mirrors gotemplate, which allows
Options("missingkey=zero").
Added simple check and simple test case.