Adapt integrated features

[sdirix]

Adapt default VS Code and Theia extensions to include more cdt-cloud showcases as well as deliver a more rounded development experience.

• Remove cmake tools
• Remove clangd-context
• Use clangd-multi-project instead of clangd
• Use VS Code extension based memory inspector instead of the Theia one
• Add serial monitor VS Code extension

[planger]

Consider adding vscode-peripheral-inspector.