Sync binary-search-tree

[mk-mxp]

• Run bin/configlet sync -u -e binary-search-tree --yes --docs --filepaths --metadata --tests include (updates the Markdown files and maybe tests.toml)
  • metadata: unsynced: binary-search-tree
• Drop strict types comments from test file and example code (these are useless)
• Add and sync test meta data to tests (uuid / @testdox in DocBlocks)
• Decide on adding / adjusting / ordering test cases to match current problem specs
  • binary-search-tree: missing 10 test cases

Do not redesign the student's interface or add test cases that would invalidate existing community solutions. These are extra tasks, which should be discussed in advance.