Change location fingerprint calculation

What does this MR do?

This MR introduces new method to calculate new location fingerprint for vulnerabilities reported by container scanning. Location fingerprint currently used in MR widget to compare vulnerabilities. This is a temporary method. Once all existing records are updated in DB we will switch fingerprint_data with

new version

 def fingerprint_data
   "#{docker_image_name_without_tag}:#{package_name}"
 end             

fingerprint_data is called from Reports::Security::Locations::Base#fingerprint (template design pattern)

Details can be found in #215466 (closed) implementation plan section

There will be a follow up MR to use new_fingerprint

Related issue

#215466 (closed)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team