Add icons to commands

[lcottercertinia]

Add icons to commands.
Will show the Certinia logo next to the Open Log Analyzer tab and next to the file name on the file list in the quick open menu

https://code.visualstudio.com/api/references/contribution-points#contributes.icons
https://code.visualstudio.com/api/references/contribution-points#contributes.commands

Examples

https://github.com/gitkraken/vscode-gitlens/blob/main/package.json#L6742
https://github.com/mhutchie/vscode-git-graph/blob/develop/package.json