Add filtering by state to PipelineSecurityReportFindingsResolver

What does this MR do?

This MR introduces a new argument for the GraphQL resolver PipelineSecurityReportFindingsResolver.

Related to #331724 (closed).

Domain information

• Security Finding: These are the vulnerability findings populated by the security analyzers and they are stored in JSON files attached to Ci::JobArtifacts.

• Vulnerability: These are the vulnerabilities already existing in the default branch of the project and stored in the database.

• Filtering by the state of a finding:

  • State of a security finding: Since these records are coming from JSON files, we determine their states on-the-fly by checking if they already have an associated vulnerability records. To do so, this MR introduces an extra SQL query to eager load the related vulnerability records from the database.
  • Filtering: After calculating the state of each finding, we iterate through all the records to filter them in-memory.

  For better understanding, the pseudo-code to calculate the state of a finding and then filtering based on that would be;

    # calculate the state of finding objects
    findings.each do |finding|
      if finding.vulnerability
        finding.state = finding.vulnerability.state
      else
        finding.state = 'detected'
      end
    end
  
    # filter by state
    findings.select { |finding| finding.state == SELECTED_STATE }

Database review

There is just one database-related change in this MR which preloads the vulnerability reords from the database for the findings by using the ActiveRecord::QueryMethods#includes(!64762 (diffs)).

An example of that query is;

SELECT
    "vulnerabilities".*
FROM
    "vulnerabilities"
WHERE
    "vulnerabilities"."id" IN (?)

And the execution plan for such query;

Index Scan using vulnerabilities_pkey on public.vulnerabilities  (cost=0.43..30.21 rows=10 width=294) (actual time=0.058..0.092 rows=10 loops=1)
   Index Cond: (vulnerabilities.id = ANY ('{1,2,3,4,5,6,7,8,9,10}'::bigint[]))
   Buffers: shared hit=44
   I/O Timings: read=0.000 write=0.000

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• [-] I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• [-] I have tested this MR in all supported browsers, or it's not needed.
• [-] I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

• [-] 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