Enhancement: Merge media snippets to the new content snippets setting

[estruyf]

Deprecate the frontMatter.dashboard.mediaSnippet setting. Merge it with the frontMatter.content.snippet setting.

[estruyf]

Ability to use multiple media snippets

[estruyf]

Added icons to highlight the snippet type

Is media snippet checkbox

Actions on the media

[estruyf]

It will be release in v7.3.0