feat: update V4 signature to pass conformance tests

[JesseLovelace]

This updates the conformance tests and adds the consistency changes necessary to make them pass, as per #84 and #85

[frankyn]

Nicely done, overall LGTM I have one question before approving.

[frankyn]

Jesse, I want to confirm that HOST_NAME can't be in the same way as BUCKET_BOUND_HOST_NAME. Is this accurate?

[codecov]

Codecov Report

Merging #114 into master will increase coverage by 0.42%.
The diff coverage is 84.61%.

@@             Coverage Diff              @@
##             master     #114      +/-   ##
============================================
+ Coverage      63.3%   63.73%   +0.42%     
- Complexity      528      539      +11     
============================================
  Files            30       30              
  Lines          4720     4740      +20     
  Branches        450      455       +5     
============================================
+ Hits           2988     3021      +33     
+ Misses         1571     1564       -7     
+ Partials        161      155       -6

Impacted Files	Coverage Δ	Complexity Δ
...n/java/com/google/cloud/storage/SignatureInfo.java	81.5% <100%> (+0.81%)	19 <0> (+2)	⬆️
...ain/java/com/google/cloud/storage/StorageImpl.java	78.72% <76.92%> (+1.91%)	119 <3> (+9)	⬆️
...rc/main/java/com/google/cloud/storage/Storage.java	80.63% <90.9%> (+0.58%)	0 <0> (ø)	⬇️

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[frankyn]

LGTM

[frankyn]

LGTM.