Implement modern arguments support for dynamic tags

[DylanPiercey]

Description

This PR makes it so that all arguments passed to the dynamic tag are prepended to the params available as tag params, that is:

<${input.renderBody}("a", "b") c d/>

When provided a render with params could receive:

<above-tag|firstArg, secondArg, attrs|>
</above-tag>

This means that it is possible via the dynamic tag to reimplement things like <for|item, index, all| in userland.

Note: This is only possible and non breaking because previously <${dynamic}(arguments)> did not parse properly. This parsing issue has been resolved, adding support for this with custom tags is not possible as it will be breaking but is planned for Marko 5.

Checklist:

• I have read the CONTRIBUTING document and have signed (or will sign) the CLA.
• I have updated/added documentation affected by my changes.
• I have added tests to cover my changes.

[codecov]

Codecov Report

Merging #1259 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1259      +/-   ##
==========================================
+ Coverage   90.47%   90.47%   +<.01%     
==========================================
  Files         336      336              
  Lines       12348    12351       +3     
==========================================
+ Hits        11172    11175       +3     
  Misses       1176     1176

Impacted Files	Coverage Δ
src/runtime/helpers.js	94.16% <100%> (+0.09%)	⬆️
src/compiler/ast/CustomTag.js	84.18% <100%> (+0.04%)	⬆️

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[coveralls]

Coverage increased (+0.002%) to 90.479% when pulling 727acb1 on dynamic-tag-modern-arguments into 2ebe7b7 on master.