Rename Sitespeed urls that moved from Editor to Source Code
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### Proposal
Some urls being tracked in our sitespeed-measurement-setup are labeled as belonging to Editor but have moved to the domain of Create:Source Code.
* `Editor_Snippets_Explore`
* `Editor_Snippet_Dashboard`
* `Editor_SingleFile_team_page`
* `Editor_Snippet_new`
* `Editor_Snippets_Textual`
* `Editor_Snippets_Multifile`
* `Editor_Snippets_Markdown`
[Dashboard](https://dashboards.gitlab.net/d/sftijGFMz/sitespeed-lcp-leaderboard?orgId=1&refresh=5m&var-namespace=sitespeed_io&var-path=desktop&var-testname=gitlab&var-domains=gitlab_com&var-pages=Editor_SingleFile_team_page&var-pages=Editor_Snippet_Dashboard&var-pages=Editor_Snippet_new&var-pages=Editor_Snippets_Explore&var-pages=Editor_Snippets_Markdown&var-pages=Editor_Snippets_Multifile&var-pages=Editor_Snippets_Textual&var-pages=SourceCode_Blob_View_Large&var-pages=SourceCode_Blob_View_Refactor_Disabled&var-pages=SourceCode_Blob_View_Refactor_Enabled&var-pages=SourceCode_Blob_View_Small&var-pages=SourceCode_DeepDirectoryView&var-pages=SourceCode_File_Blame_Large&var-pages=SourceCode_File_Blame_Small&var-pages=SourceCode_HighlightJs__Enabled&var-pages=SourceCode_Repo_Large&var-pages=SourceCode_Repo_Small&var-browser=chrome&var-function=median&var-connectivity=cable)
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