refactor(VParallax): update for v2

[johnleider]

relied on translate to be called in order to boot, this doesn't occur when image is the same size as
the container

fixes #7010

Description

Motivation and Context

How Has This Been Tested?

Markup:

// Paste your FULL Playground.vue here

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Improvement/refactoring (non-breaking change that doesn't add any feature but make things better)

Checklist:

• The PR title is no longer than 64 characters.
• The PR is submitted to the correct branch (master for bug fixes and documentation updates, dev for new features and breaking changes).
• My code follows the code style of this project.
• I've added relevant changes to the documentation (applies to new features and breaking changes in core library)

[codecov]

Codecov Report

Merging #7042 into next will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##             next   #7042      +/-   ##
=========================================
+ Coverage   79.87%   79.9%   +0.02%     
=========================================
  Files         328     328              
  Lines        8383    8384       +1     
  Branches     2134    2134              
=========================================
+ Hits         6696    6699       +3     
+ Misses       1600    1599       -1     
+ Partials       87      86       -1

Impacted Files	Coverage Δ
...ages/vuetify/src/components/VParallax/VParallax.ts	79.16% <100%> (+9.6%)	⬆️

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