Simplify overcomplicated build script - Phase 1

[codeconsole]

1. Delete buildSrc
2. Delete settings.gradle
3. Replace top of build.gradle

with

buildscript {
    repositories {
        maven { url "https://repo.grails.org/grails/core/" }
    }
    dependencies {
        classpath "org.grails:grails-gradle-plugin:7.0.0-SNAPSHOT"
    }
}

plugins {
    id "com.bertramlabs.asset-pipeline" version "5.0.1"
    id "com.github.erdi.webdriver-binaries" version "3.2"
    id "war"
    id "idea"
    id "application"
    id "com.github.ben-manes.versions" version "0.51.0"
}
apply plugin:"org.grails.grails-web"
apply plugin:"org.grails.grails-gsp"

Phase 2: Get ride of buildscript {} by publishing to Grails Gradle plugin to Gradle plugin repo.