Datafusion 52 upgrade (#5863)

This PR uses the current tip of DataFusion to test the upcoming upgrade.
It drops the use of the `SchemaAdapter` API, removes the vendored code
we pulled to fix some bugs and currently passes all of our tests!

This PR requires at least one more round of polish, I'm sure I left some
convoluted things in `opener.rs`.

~Waiting for the upstream release
apache/datafusion#18566

---------

Signed-off-by: Adam Gutglick <[email protected]>

Author: AdamGS

.gitignore

@@ -224,3 +224,6 @@ compile_commands.json
 # cargo sweep output
 sweep.timestamp
 
+# Pending cargo-insta snapshots
+*.pending-snap
+