Prefix function names with spring-

* Add `spring-` prefix to function names

Fixes: #9

This commit renames each sub-module in the common, consumer, function
and supplier groups with a prefix of `spring-`.

* Update README.adoc links to new prefixed names

function/spring-aggregator-function/build.gradle

@@ -0,0 +1,18 @@
+dependencies {
+    api project(':spring-payload-converter-function')
+    api 'org.springframework.integration:spring-integration-mongodb'
+    api 'org.springframework.integration:spring-integration-redis'
+    api 'org.springframework.integration:spring-integration-jdbc'
+
+    runtimeOnly 'org.springframework.boot:spring-boot-starter-data-redis'
+    runtimeOnly 'org.springframework.boot:spring-boot-starter-data-mongodb'
+    runtimeOnly 'org.springframework.boot:spring-boot-starter-jdbc'
+    runtimeOnly 'org.hsqldb:hsqldb'
+    runtimeOnly 'com.h2database:h2'
+    runtimeOnly 'org.mariadb.jdbc:mariadb-java-client'
+    runtimeOnly 'org.postgresql:postgresql'
+
+    testImplementation 'org.testcontainers:mongodb'
+    testImplementation project(':spring-mongodb-consumer').sourceSets.test.output
+    testImplementation project(':spring-redis-consumer').sourceSets.test.output
+}