Aggregate multiple abuse reports by the user & category (list-view)

What does this MR do and why?

• Resolves https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/180
• It aggregates open abuse reports by user & abuse category, such as User1 has been reported for spam by 10 users. Earlier it would list each abuse report as it's own row.

Frontend:

• Adds a new sorting option, Number of Reports for open reports. This is the default sorting option for open reports.
• Since, closed reports are not aggregated, their default sorting option is still Created date
• Fixes a minor bug in the filter bar, so that Status = X always appears first.

Backend:

• Updates AbuseReportsFinder so it aggregates and sorts open reports. Closed reports don't get aggregated. Since, we get a lot of abuse reports, aggregating closed reports would have been not as performative.
• Adds count to the AbuseReportEntity with a default = 1.

Database

No changes have been made to the tables, but here are the query plans for the new query

Insert Data

# status = closed & category = 1 (10K)
exec INSERT INTO "abuse_reports" ("reporter_id", "user_id", "message", "created_at", "updated_at", "message_html", "cached_markdown_version") SELECT 9670031, user_id, 'spammer', '2023-02-07 09:51:12.678028', '2023-02-07 09:51:12.678028', 'spammer', 2097152 FROM generate_series(4038079, 4048079) as user_id;
 
# status = open & category = 1 (10K)
exec INSERT INTO "abuse_reports" ("reporter_id", "user_id", "message", "created_at", "updated_at", "message_html", "cached_markdown_version", "category", "status") SELECT 9670031, user_id, 'spammer', '2023-02-07 09:51:12.678028', '2023-02-07 09:51:12.678028', 'spammer', 2097152, 1, 2 FROM generate_series(4038079, 4048079) as user_id;

# status = open & category = 1 & user_id = 9670032 (1K)
exec INSERT INTO "abuse_reports" ("user_id", "reporter_id", "message", "created_at", "updated_at", "message_html", "cached_markdown_version") SELECT 9670032, reporter_id, 'spammer', '2023-02-07 09:51:12.678028', '2023-02-07 09:51:12.678028', 'spammer', 2097152 FROM generate_series(4038079, 4039079) as reporter_id;

• status = open
• status = open and category = spam
• status = open and user_id = 9670032
• status = open and reporter_id = 9670031

Screenshots or screen recordings

Before	After
before	after

How to set up and validate locally

1. In rails console

> Feature.enable(:abuse_reports_list)

# seed data
> AbuseReport.delete_all

# create 10 different reports for the same user & category
> User.limit(10).order_id_asc.pluck("id").each { |i| AbuseReport.create(reporter_id: i, user_id: User.last.id, status: "open", category: "spam", message: "test") }

# create another 10 for the same user but different category
> User.limit(10).order_id_asc.pluck("id").each { |i| AbuseReport.create(reporter_id: i, user_id: User.last.id, status: "open", category: "offensive", message: "test") }

# create 20 more for different users
> User.limit(20).order_id_asc.pluck("id").each { |i| AbuseReport.create(reporter_id: User.first.id, user_id: i, status: "open", category: "crypto", message: "test") }

2. Log-in as admin and navigate to /admin/abuse_reports

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.