Add reported from field to abuse report form

What does this MR do and why?

• Adds a Reported From field to the report abuse form which is supposed to contain the link to the issue/MR/user/comment that is being reported for abuse.
• Updated the text & UI of the form based on the Figma design in the issue, https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/132/

Database Migration

- Output of db:migrate

main: == 20221212054640 AddReportedFromToAbuseReports: migrating ====================
main: -- transaction_open?()
main:    -> 0.0000s
main: -- column_exists?(:abuse_reports, :reported_from_url)
main:    -> 0.0208s
main: -- add_column(:abuse_reports, :reported_from_url, :text, {:null=>false, :default=>""})
main:    -> 0.0015s
main: -- transaction_open?()
main:    -> 0.0000s
main: -- current_schema()
main:    -> 0.0003s
main: -- transaction_open?()
main:    -> 0.0000s
main: -- execute("ALTER TABLE abuse_reports\nADD CONSTRAINT check_ab1260fa6c\nCHECK ( char_length(reported_from_url) <= 512 )\nNOT VALID;\n")
main:    -> 0.0009s
main: -- current_schema()
main:    -> 0.0003s
main: -- execute("SET statement_timeout TO 0")
main:    -> 0.0004s
main: -- execute("ALTER TABLE abuse_reports VALIDATE CONSTRAINT check_ab1260fa6c;")
main:    -> 0.0006s
main: -- execute("RESET statement_timeout")
main:    -> 0.0004s
main: == 20221212054640 AddReportedFromToAbuseReports: migrated (0.0422s) ===========

- Output of db:rollback

main: == 20221212054640 AddReportedFromToAbuseReports: reverting ====================
main: -- transaction_open?()
main:    -> 0.0000s
main: -- column_exists?(:abuse_reports, :reported_from_url)
main:    -> 0.0121s
main: -- remove_column(:abuse_reports, :reported_from_url)
main:    -> 0.0013s
main: == 20221212054640 AddReportedFromToAbuseReports: reverted (0.0314s) ===========

Screenshots or screen recordings

Before	After
	after

Validating the URL

How to set up and validate locally

1. Log-in as admin
2. Go to a user's profile, such as http://localhost:3000/aubrey_schaefer
3. Click on Report abuse to administrator
4. You can also go to an issue created by another user and click on Issue Actions -> Report abuse to administrator

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.

Related to https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/132/