[Core] Implement TeamCity output format plugin

[mpkorstanje]

Summary

This plugin inserts markers that can be picked up by IDEA and
Teamcity. These in turn can then use this information to display a
test tree and show the output grouped by scenario.

This is plugin is nessesary because Intelij uses reflection
to extract more information from the plugin system then what would
normally be available. By substituting the CucumberJvm[1-5]SMFormatter
with this plugin we avoid runtime errors when our internals inevitably change.

Unfortunately the teamcity format is poorly documented[1]. Reverse
engingeering[2][3] the format from the plugin yields some information
but the exact function is rather opaque.

1. https://confluence.jetbrains.com/display/TCD9/Build+Script+Interaction+with+TeamCity
2. https://github.com/JetBrains/intellij-community/tree/master/plugins/cucumber-jvm-formatter5/src/org/jetbrains/plugins/cucumber/java/run
3. https://github.com/JetBrains/intellij-community/tree/master/plugins/cucumber-jvm-formatter/src/org/jetbrains/plugins/cucumber/java/run

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).

Checklist:

• I've added tests for my code.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.