CB-13145: added variable replacing to framework tag

[stevengill]

Still need to add a test.

This is for allowing framework tags in plugin.xml to have variables defined and replaced via the <preference> tag also in plugin.xml

Example

<preference name="FCM_VERSION" default="11.0.1"/>

<framework src="com.google.firebase:firebase-messaging:$FCM_VERSION"/>

$FCM_VERSION would get replaced with 11.0.1 when being written to project.properties and build.gradle.

[stevengill]

This pr needs to be linked with cordova-lib to test this functionality.

[codecov-io]

Codecov Report

Merging #4 into master will decrease coverage by 0.08%.
The diff coverage is 76.92%.

@@            Coverage Diff             @@
##           master       #4      +/-   ##
==========================================
- Coverage   84.42%   84.33%   -0.09%     
==========================================
  Files          19       19              
  Lines        1746     1756      +10     
  Branches      369      373       +4     
==========================================
+ Hits         1474     1481       +7     
- Misses        272      275       +3

Impacted Files	Coverage Δ
src/PluginManager.js	92.45% <100%> (ø)	⬆️
src/PluginInfo/PluginInfo.js	76.13% <75%> (-0.37%)	⬇️

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[goya]

id use global variable elements for this. preferences should be used for platform or core use. the preference namespace should be explicitly different to an assumed namespace of regex for random plugin authors.