338|UI: Display current frame number in media time into Note Edition panel and space 'time'

Description of feature

• Created scene.media_current_frame property to set the global time using the media time.
• Display current frame number in media time into Note Edition panel and space "time".

How to test it

Checklist

Please check if your MR fulfills the following requirements:

• Unit tests have been added, if possible
• Documentation has been updated
• Build was run locally and any changes were pushed
• Lint has passed locally without error
• CHANGELOG.md has been updated

FYI: @awesome_dev_too