cp: support uploads larger than 100 MiB (createUploadSession)

[lionello]

upload() does a single PUT .../content, which the API caps at 100 MiB. Larger files fail with a 404 and the CLI prints "Skipped. Uploads larger than 100MiB are not yet supported."

The classic API supports resumable uploads:

POST /drive/root:/{path}:/createUploadSession
PUT  {uploadUrl}          Content-Range: bytes 0-10485759/{total}

Chunks must be a multiple of 320 KiB. The session response carries nextExpectedRanges, so an interrupted upload can be resumed rather than restarted.

Notes:

• upload() currently gzips the whole body in memory (call() does Zlib.gzipSync) and verifies the SHA1 of the buffer afterwards. A chunked path needs to stream from disk instead, and can verify the SHA1 from the final item response.
• @name.conflictBehavior is passed on the session-creation POST, not per chunk. See overwrite existing files #22.

README TODO: "Uploads larger than 100MiB are not yet supported (needs range API)".