RecordingStream monkey-patched functions result in mypy errors

[jleibs]

We money-patch a bunch of helpers into the RecordingStream class, but in practice using these causes mypy to produce a bunch of errors.

For example

rerun_py/rerun_sdk/rerun/blueprint/api.py:77: error: "RecordingStream" has no attribute "log"  [attr-defined]
rerun_py/rerun_sdk/rerun/blueprint/api.py:84: error: "RecordingStream" has no attribute "log"  [attr-defined]
rerun_py/rerun_sdk/rerun/blueprint/api.py:184: error: "RecordingStream" has no attribute "log"  [attr-defined]
rerun_py/rerun_sdk/rerun/blueprint/api.py:292: error: "RecordingStream" has no attribute "log"  [attr-defined]
rerun_py/rerun_sdk/rerun/blueprint/api.py:314: error: "RecordingStream" has no attribute "set_time_seconds"  [attr-defined]
rerun_py/rerun_sdk/rerun/blueprint/api.py:318: error: Returning Any from function declared to return "MemoryRecording"  [no-any-return]
rerun_py/rerun_sdk/rerun/blueprint/api.py:318: error: "RecordingStream" has no attribute "memory_recording"  [attr-defined]

Now that we've introduced code-gen into other parts of our code-base, we should consider just code-genning these helpers to cut down on runtime shenanigans and bring us proper type signatures.