update to new dokka plugin

[robstoll]

Non-Code related feature

Atrium is currently using dokka 0.9.8 via the tutteli-dokka plugin.
We would like to update to dokka 1.4.10

Following the things we need to do (see #683 most likely you can build on this):

• remove classpath "ch.tutteli:tutteli-gradle-dokka:$tutteli_plugins_version" from build.gradle
• configure the new dokka plugin instead. You don't have to bother what was configured before, you can start from scratch but we have the following requirements:
  • we need only the html report (disable the rest)
  • make sure it is not included in the normal build (./gradlew build should not trigger it) - might be this is already the case. Use ./gradlew atrium-core-api-jvm:build --dry-run and check if dokka is included. If it is, then find ways to deactivate it. We want to be able to run dokka separately
  • check if the samples for toBe are correctly rendered
• we still want an overall report when running ghPages. You probably need to adapt gradle/scripts/gh-pages.gradle => see https://github.com/Kotlin/dokka/blob/master/runners/gradle-plugin/MIGRATION.md and https://github.com/Kotlin/dokka#multi-module-projects
  => make sure we still suppress the packages defined at the end of the gh-pages.gradle script.

Hint, the following might help to setup the plugin, note thought that Atrium is using groovy and not kotlin for gradle
https://github.com/Kotlin/dokka#using-dokka

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[jgrgt]

I'll work on this

[robstoll]

fixed with #1386