Cleanup workflows.

[mshima]

Remove:

• choose between gradle or maven if duplicated (maven and gradle dependency test should be tested by microservice full stack).
• duplicate backend test if frontend features is tested by others tests.

Workflows:

• ngx-mariadb-oauth2-infinispan -> ngx-gradle-mariadb-oauth2-infinispan
• ngx-gradle-mongodb-kafka-cucumber -> ngx-mongodb-kafka-cucumber
• ngx-gradle-mysql-es-noi18n-mapsid -> ngx-mysql-es-noi18n-mapsid
• react-maven-mysql-es-noi18n-mapsid -> react-gradle-mysql-es-noi18n-mapsid
• react-maven-cassandra-session-redis -> react-gradle-cassandra-session-redis
• react-gradle-h2mem-memcached -> react-maven-h2mem-memcached
• vue-oauth2 -> vue-noi18n-ws-oauth2
• vue-mongodb-kafka-cucumber -> ngx-mongodb-kafka-cucumber
• webflux-gateway-jwt -> microservice full stack with jwt
• webflux-gateway-oauth2 -> microservice full stack with oauth2
• webflux-mongodb-es-session -> webflux-gradle-session-mariadb-es (mongodb has 2 other tests, focus on session-es)

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