commit #45 - Adding sentiment analysis service

...main/java/app/analysis/entailment/EntailmentAnalzser.java

...c/main/java/app/analysis/sentiment/SentimentAnalyzer.java

.../java/app/analysis/sentiment/SentimentClassification.java

...src/main/java/app/analysis/sentiment/SentimentResult.java

ompp-api/src/main/java/app/api/LecturerController.java

...api/src/main/java/app/configurations/ConnectorConfig.java

ompp-api/src/main/java/app/entities/AnswerEntity.java

ompp-api/src/main/java/app/pojo/WordDetails.java

ompp-api/src/main/java/app/services/SentimentService.java

ompp-api/src/main/resources/application.properties

ompp-api/src/main/resources/stopwords.txt

.../StudentResponseChart/student-response-chart.component.ts