[Plugin] Add an option to fail on deprecated usages

[martinbonnin]

Add

apollo {
  warnOnDeprecatedUsages.set(true) // true by default
  failOnWarnings.set(true) // false by default
}

Fixes #2489

Using the w: $file: ($line, $column): $message format, intelliJ will display it nicely in the "Run" panel:

Somehow the warnings are not clickable in the "Run" panel but are in the build output, not really sure how to make IntelliJ pick them up.

Also, this PR only checks deprecated fields usages. Checking for deprecated enums could be done too but that's more complex so will be done in a future PR.

Ping @kenyee, sorry it took so long, I wanted to get the multi-module PR in first to avoid too many conflicts.

[tasomaniac]

Thanks for working on this. It's a great addition.