[go-migration] Add dependencies to application classpath after staging

[kiril-keranov]

The PR addresses issues related to not adding corresponding framework jar dependencies to the application classpath after staging.

• deps/index/env/CLASSPATH is overwritten and further unused on actual startup
  The corresponding dependencies frameworks that should provide jars to the application classpath are now fixed to append to the CLASSPATH env sourced from profile.d. Instead of rewriting a CLASSPATH variable in deps/index/env they provide sh scripts in the profile.d folder which assemble the CLASSPATH env when sourced.
• tomcat and spring-boot containers never considered these dependencies to be added to the classpath on issuing the final release command. They are now adjusted to provide a shell script that will build symlinks to these dependencies in the corresponding WEB-INF/lib or BOOT-INF/lib application dependencies folders in order for the dependencies to be subject of application classloading.
• Remove usage of -Xbootclasspath/a and use -classpath. One of the occasions for the container security provider, which is now added with the application classloader as usual, also fixed for tomcat-logging-support added from setenv script.
• Cleanup of abundant context struct used in finalize
  Addresses issue

[ramonskie]

looks good.