Add "Copy #include file" action button

[ReinhardKeil]

The "Copy #include file" action button should copy #include "<filename>"/n to the clip board.

It should be on components that provide header files and header files in the CMSIS View as shown in this mockup.

For components:

• the API header file gets priority
• otherwise the first header file is used.

[edriouk]

The following should appear in a command handler:

 const incText = `#include "${path.basename(uri.fsPath)}"`;
 await vscode.env.clipboard.writeText(incText)

[mguzmanm]

This functionality will come later after refactoring CMSIS View #193 Refactor CMSIS View