FIX - EPUB validation module based on W3C's EPUBCheck

[carlwilson]

This change is to add the EPUB-ptc extension module version 1.0. The module wraps the W3C EPUBCheck validation tool as a JHOVE module.

Some notes in advance of full documentation:

1. Tests use examples derived from IDPF's EPUB 3 samples and test suite on GitHub and National Library of the Netherlands / Research epubPolicyTests, also on GitHub. These may be useful for additional test material.
2. The checkSignatures() method is based on the Library of Congress EPUB2and EPUB3 documentation. For this valid is always set to UNDETERMINED. This check only looks at "magic numbers" and file extension. If the signature matches, it sets "well formed" to true. Note that it does not perform the additional package checks that contribute to "well formed"-ness in parse() so there is a small inconsistency there.
3. Well-formed/valid status is currently dependent on the messages returned by EPUBCheck (except when a non EPUB is passed and it throws an exception see this issue). The full list of possible messages and their severity according to EPUBCheck can be seen here.
   • an EPUB is well formed if it has no messages with (severity="FATAL") or (severity="ERROR" and message-id begins with "PKG-"). In other words, fatal errors and package errors make the file "Not well formed".
   • If well formed, an EPUB is not valid if it has any messages with severity="ERROR".
4. The EPUBCheck provides a lot of interesting properties that I've included in the JHOVE report. Some of them may affect preservation decisions, so I thought they seemed useful. For example, the presence of encryption, external fonts, or resources that are stored remotely but visually or aurally embedded in the EPUB. The result is an unusually large property/value section! You can review what is included here and here.

Includes #460 contributed by @karenhanson

[codecov]

Codecov Report

Merging #543 into integration will increase coverage by 0.2%.
The diff coverage is n/a.

@@               Coverage Diff                @@
##             integration     #543     +/-   ##
================================================
+ Coverage          49.44%   49.65%   +0.2%     
- Complexity           984      992      +8     
================================================
  Files                 56       56             
  Lines               7768     7768             
  Branches            1409     1409             
================================================
+ Hits                3841     3857     +16     
+ Misses              3457     3445     -12     
+ Partials             470      466      -4

Impacted Files	Coverage Δ	Complexity Δ
.../edu/harvard/hul/ois/jhove/handler/XmlHandler.java	63% <0%> (+0.27%)	266% <0%> (+2%)	⬆️
...src/main/java/edu/harvard/hul/ois/jhove/Utils.java	72.22% <0%> (+2.38%)	29% <0%> (+1%)	⬆️
...c/main/java/edu/harvard/hul/ois/jhove/RepInfo.java	56.92% <0%> (+3.84%)	40% <0%> (+4%)	⬆️

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