Move OAuth2 examples to separate folder

Author: alex268

auth/oauth2_token/pom.xml renamed to auth/oauth2_token_exchange/jwt_token/pom.xml

@@ -9,7 +9,7 @@
     </parent>
 
     <artifactId>ydb-java-example-auth-oauth2-token-credentials</artifactId>
-    <name>OAuth2 Token Example</name>
+    <name>YDB OAuth2 Token Example</name>
     <packaging>jar</packaging>
 
     <dependencies>

auth/oauth2_token/src/main/java/tech/ydb/example/Main.java renamed to auth/oauth2_token_exchange/jwt_token/src/main/java/tech/ydb/example/Main.java

@@ -9,7 +9,7 @@
     </parent>
 
     <artifactId>ydb-java-example-auth-oauth2-key-credentials</artifactId>
-    <name>OAuth2 Private Key Example</name>
+    <name>YDB OAuth2 Private Key Example</name>
     <packaging>jar</packaging>
 
     <dependencies>

auth/oauth2_private_key/pom.xml renamed to auth/oauth2_token_exchange/private_key/pom.xml

@@ -23,7 +23,7 @@
         <module>metadata_credentials</module>
         <module>service_account_credentials</module>
         <module>static_credentials</module>
-        <module>oauth2_token</module>
-        <module>oauth2_private_key</module>
+        <module>oauth2_token_exchange/jwt_token</module>
+        <module>oauth2_token_exchange/private_key</module>
     </modules>
 </project>