Issue title: wishlist: add button to clear all placed parts
 Issue body: it would be nice to have a button which would clear all placed parts for a second assembly, currently I have to manually uncheck all parts or group of parts
 Comments: 
 Comment 0: Double click checkbox column header to set/unset all.
{'source': 'GithubIssues', 'repo_name_with_owner': 'openscopeproject/InteractiveHtmlBom', 'issue_id': 761967249, 'repo_stars': 2510.0}