test: refactor test-fs-read-*

* Use `common.mustNotCall()` in place of `common.noop` where appropriate
* Increase specificity of regular expressions (that is, make them match
  the whole error string rather than part of the error string) in
  `assert.throws()` calls

PR-URL: https://github.com/nodejs/node/pull/13501


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>