Support filtering metrics in the internal events cli

What does this MR do and why?

Adds support for defining metrics which the filter by the event's additional properties in the Internal Events CLI. For events without additional properties or metrics without filters, the flow stays mostly the same.

• Related issue: #434506 (closed)
• MR that added the flow for events: !153334 (merged)

Changes in the metric creation flow:

• adds filter-based options to the metric selection screen (Scope)
  • adds the list of selected metrics at the top of the screen with an indicator of which additional properties are available for each event
• adds an extra step for users to manually set the key_path/filename for metrics with filters
• prompts users to manually set the key_path/filename when the filename is too long or there are key_path conflicts
• when writing descriptions for metrics, a simplified metric description is used instead of a "technical" description
  • the list of selected events is now at the top of the page shown alongside the event descriptions & filters (where applicable)
• when a user creates a metric with filters that includes multiple events, the user is prompted to confirm inclusion of the event in the metric

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Full flow for metric for a single event filtering on label

Flow for metric for a multiple events, filtering on different properties with the same meaning

Flow for metric for a multiple events, with some events not filterable

How to set up and validate locally

1. run ruby scripts/internal_events/cli.rb
2. follow the above screenshots to walk through the new flows