publish as catena-corpus on PyPI and npm

Both registries already have a `catena`: an HPE blockchain client on PyPI,
and a JavaScript OOP wrapper at 2.2.0 on npm. Neither is going anywhere, so
the distributions take a name that is free on both.

The Python import is unaffected — a distribution name and a module name are
independent there, so `pip install catena-corpus` still gives `import
catena`, and nothing in the examples or the bindings changes. On npm the
package name is the import specifier, so that one does change: `import
{ chunkMarkdown } from "catena-corpus"`.

The crates keep their own names. `catena` is free on crates.io.

crates/bindings/pyproject.toml

@@ -3,7 +3,7 @@ requires = ["maturin>=1.9,<2.0"]
 build-backend = "maturin"
 
 [project]
-name = "catena"
+name = "catena-corpus"
 description = "The catena libraries behind one surface, for calling in process rather than as a subprocess"
 readme = "README.md"
 license = "MPL-2.0"