Dataframe v2: make `num_rows` aware of filters and such #13323

Job	Run time
cpp-paths-filter	5s
docs-paths-filter	5s
python-paths-filter	8s
rust-paths-filter	5s
web-paths-filter	4s
Checks / Rerun lints	34s
Checks / Check if running codegen would produce any changes	1m 17s
Checks / Check links	28s
Checks / Lint markdown	14s
Checks / Misc formatting	14s
Checks / Spell Check	6s
Update PR Body / Update PR body	15s
Deploy Landing Preview	0s
C++ tests	0s
Rust Checks / Test on macOS and Windows	0s
Rust Checks / Rust lints (fmt, check, clippy, tests, doc)	6m 56s
Build web viewer / Build web viewer	2m 42s
Build rerun_js / Build rerun_js	3m 43s
Python Checks / Test Python Docs	28s
Python Checks / Python lints (ruff, mypy, …)	34s
Minimum CLI Build / Set Config (linux-x64)	1s
Minimum CLI Build / Build rerun-cli (ubuntu-latest-16-cores)	3m 44s
Upload Web / Upload web build to google cloud (wasm32 + wasm-bindgen)	37s
Save PR Summary	0s
Minimum Wheel Build / Set Config (linux-x64)	4s
Minimum Wheel Build / Build Wheels (ubuntu-latest-16-cores)	1m 2s
Minimum Wheel Test	0s
	23m 26s

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