refactor: remove unused e-mail controller

elimu-ai/wiki#194

Author: jo-elimu

pom-dependency-tree.txt

@@ -1,4 +1,4 @@
-ai.elimu:webapp:war:2.6.111-SNAPSHOT
+ai.elimu:webapp:war:2.6.112-SNAPSHOT
 +- ai.elimu:model:jar:model-2.0.118:compile
 |  \- com.google.code.gson:gson:jar:2.13.1:compile
 |     \- com.google.errorprone:error_prone_annotations:jar:2.38.0:compile
@@ -20,11 +20,6 @@ ai.elimu:webapp:war:2.6.111-SNAPSHOT
 +- org.apache.logging.log4j:log4j-slf4j2-impl:jar:2.24.3:runtime
 |  \- org.slf4j:slf4j-api:jar:2.0.16:compile
 +- commons-lang:commons-lang:jar:2.6:compile
-+- commons-validator:commons-validator:jar:1.9.0:compile
-|  +- commons-beanutils:commons-beanutils:jar:1.9.4:compile
-|  +- commons-digester:commons-digester:jar:2.1:compile
-|  +- commons-logging:commons-logging:jar:1.3.2:compile
-|  \- commons-collections:commons-collections:jar:3.2.2:compile
 +- org.apache.commons:commons-csv:jar:1.14.0:compile
 |  +- commons-io:commons-io:jar:2.18.0:compile
 |  \- commons-codec:commons-codec:jar:1.18.0:compile

pom.xml

@@ -372,11 +372,6 @@
       <artifactId>commons-lang</artifactId>
       <version>2.6</version>
     </dependency>
-    <dependency>
-      <groupId>commons-validator</groupId>
-      <artifactId>commons-validator</artifactId>
-      <version>1.9.0</version>
-    </dependency>
     <dependency>
       <groupId>org.apache.commons</groupId>
       <artifactId>commons-csv</artifactId>