Migrate QuerydslDataFetcher to use fluent Querydsl API

Remove supporting classes for external projection as projections are
handled by Spring Data directly.

See gh-168

Author: mp911de

build.gradle

@@ -59,7 +59,7 @@ configure(moduleProjects) {
 			mavenBom "com.fasterxml.jackson:jackson-bom:2.12.5"
 			mavenBom "io.projectreactor:reactor-bom:2020.0.11"
 			mavenBom "org.springframework:spring-framework-bom:5.3.10"
-			mavenBom "org.springframework.data:spring-data-bom:2021.0.5"
+			mavenBom "org.springframework.data:spring-data-bom:2021.1.0-RC1"
 			mavenBom "org.springframework.security:spring-security-bom:5.5.2"
 			mavenBom "org.jetbrains.kotlin:kotlin-bom:1.5.31"
 			mavenBom "org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.5.2"

samples/webmvc-http/build.gradle

@@ -13,6 +13,9 @@ dependencies {
 	implementation 'org.springframework.boot:spring-boot-starter-hateoas'
 	implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
 	implementation 'org.springframework.boot:spring-boot-starter-actuator'
+	// TODO: Remove after upgrade to Spring Boot 2.6
+	implementation 'org.springframework.data:spring-data-commons:2.6.0-RC1'
+	implementation 'org.springframework.data:spring-data-jpa:2.6.0-RC1'
 	implementation 'com.querydsl:querydsl-core'
 	implementation 'com.querydsl:querydsl-jpa'
 	developmentOnly 'org.springframework.boot:spring-boot-devtools'

spring-graphql/build.gradle

@@ -31,7 +31,9 @@ dependencies {
 	testImplementation 'org.springframework:spring-websocket'
 	testImplementation 'org.springframework:spring-test'
 	testImplementation 'org.springframework.data:spring-data-commons'
+	testImplementation 'org.springframework.data:spring-data-keyvalue'
 	testImplementation 'com.querydsl:querydsl-core'
+	testImplementation 'com.querydsl:querydsl-collections'
 	testImplementation 'javax.servlet:javax.servlet-api'
 	testImplementation 'com.fasterxml.jackson.core:jackson-databind'