Migration to Gradle 8.11 and Dokka 2.0

[philips77]

This PR fixes all warnings, deprecations and migrates Dokka to V2 using https://kotlinlang.org/docs/dokka-migration.html

It may be required for some time for projects to add a flag in gradle.properties:

org.jetbrains.dokka.experimental.gradle.pluginMode=V2Enabled

See: https://kotlinlang.org/docs/dokka-migration.html#set-the-opt-in-flag

Nordic Dokka Plugin

This PR also creates a new plugin: no.nordicsemi.plugin.dokka which applies Nordic look & feel to the generated documentation. This has to be added to the main build.gradle.kts file using:

plugins {
    // [...]

    alias(libs.plugins.nordic.dokka) apply true
}

[philips77]

The Nordic style does not get applied to javadoc files in binaries distributed on Maven, just do /docs folder, which is populated to GitHub Pages.