Add ribbon to <monochrome /> icon

[mateuszkwiecinski]

#482

I haven't figured out a way how AGP transforms monochrome icons yet so it doesn't fix the linked issue, but this PR makes the plugin recognize custom icon resource passed via <monochrome /> tag

[codecov]

Codecov Report

Merging #483 (db9cf3d) into master (acd2848) will increase coverage by 0.01%.
The diff coverage is 86.66%.

@@             Coverage Diff              @@
##             master     #483      +/-   ##
============================================
+ Coverage     80.82%   80.84%   +0.01%     
  Complexity      114      114              
============================================
  Files            16       16              
  Lines           631      642      +11     
  Branches        100      102       +2     
============================================
+ Hits            510      519       +9     
  Misses           49       49              
- Partials         72       74       +2     

Files Changed	Coverage Δ
.../starter/easylauncher/plugin/EasyLauncherPlugin.kt	67.02% <50.00%> (-0.73%)	⬇️
...ct/starter/easylauncher/plugin/EasyLauncherTask.kt	75.92% <75.00%> (-1.00%)	⬇️
...m/project/starter/easylauncher/plugin/XmlReader.kt	75.00% <100.00%> (+3.00%)	⬆️
...ect/starter/easylauncher/plugin/models/IconFile.kt	100.00% <100.00%> (ø)