provide a "copy to clipboard" button in the preview windows for the code block

[suredream]

Please select if your request is either something new or an enhancement

• Enhancement of an existing Feature.
• Request of a new feature.

Please select the area your request applies to. (Multiple selections are Possible. You can leave blank if you're not sure.)

• Workspace - VSCode workspace, vaults, Intellisense/autocomplete, Dendron settings
• Lookup - Dendron's Lookup Command
• Views - Dendron Preview, Tree View, Side Panels in the UI
• Schema - Dendron Schemas
• Pod - Data import from / export to Dendron
• Publish - External Site Publish
• Markdown - Markdown features, such as syntax support and features

Describe the solution you'd like

As many other editors, a quick copy of the code block to the clipboard will accelerate the editing a lot.

Describe alternatives you've considered

Can be a visible button, or click on the code block area, then the content will be copy to the clipboard, that would be great.

Additional context