Add number of approval project rules to usage ping

What does this MR do?

Related issue: #220529 (closed)

Adds usage ping for:

• Number of project approval rules
• Number of project approval rule with Target branch rule option is not the default (Any branch)

count(ApprovalProjectRule)

SELECT COUNT(approval_project_rules.id) FROM approval_project_rules WHERE approval_project_rules.id BETWEEN 1 AND 100000

Query Plan: https://explain.depesz.com/s/EoXE

Planning time: 0.130ms
Execution time: 15.602ms

count(ApprovalProjectRule.joins(:protected_branches))

SELECT COUNT(approval_project_rules.id) FROM approval_project_rules INNER JOIN approval_project_rules_protected_branches ON approval_project_rules_protected_branches.approval_project_rule_id = approval_project_rules.id INNER JOIN protected_branches ON protected_branches.id = approval_project_rules_protected_branches.protected_branch_id WHERE approval_project_rules.id BETWEEN 1 AND 100000

Query Plan: https://explain.depesz.com/s/T2nw

Planning time:	3.244ms
Execution time:	47.538ms