Blobfile

* Add convenience `read_text` / `read_bytes` / `write_text` / `write_bytes` functions
* Track versions in Azure streaming files, expose `last_version_seen`
* Note that blobfile will now raise a `VersionMismatch` error if a file is modified between
issuing read API calls to Azure blob storage
* Improve exception handling to avoid issue where Python keeps alive multiple references to same
buffer, resulting in BufferError
* Fix glob for Azure blobs with unicode characters (turns out Azure has a weird definition of
alphabetical)
* Make DNS logic more robust
* Loosen bounds on dependencies
* Remove use of deprecated `utcnow`

* Restore support for Python 3.8

* Support resolving objects that define `__blobpath__`
* Drop support for Python 3.7
* Remove hack to work around old versions of `requests` (if you use `requests`, use 2.26 or newer)
* Various type checking, linting and test changes

* Support a `version` parameter for writing files to Azure, if the `version` doesn't match the remote version, a `VersionMismatch` error will be raised from williamzhuk

* Fix for storing access tokens on a different filesystem than the one used for temp directories from hponde

* Change `configure` defaults to `output_az_paths=True` and `save_access_token_to_disk=True`