Fixes some warnings and errors in JavaDoc

Whats done:

• Fixed error when building framework-api:javadoc in AbstractPdfView.java
• Fixed incorrect links in ScenariosForSpringSecurityExpressionTests.java and ServletRequestUtilsBenchmark.java
• Fixed warnings (shown es errors) Cannot resolve symbol 'https' -> Replace URL with HTML Link
• Fixed method references

Note

Pull request is for 6.1.x version as we have build error here (and main too)