api: rename `strict` to `pass_through`

[MarcoGorelli]

Context: in both the Plotly and the Altair PRs, some maintainers expressed some surprised at what strict=False does

Polars does have strict parameter in a few places, but it doesn't exactly match ours in from_native:

• for strict=True, both Narwhals.from_native and Polars' Series constructor raise
• for strict=False, then in Polars, non-coercible types are set to null, whereas in narwhals.from_native we just pass things through unchanged

So, pass_through is probably a better name

An alternative would be to be to just make it strict by default and let people do try-except, but tbh I'm not a huge fan of encouraging try-except, it's kinda error-prone, and it's easy to think you're catching one error but are actually catching another one entirely

[MarcoGorelli]

in accordance with the stability principle, the idea would be to:

• introduce pass_through alongside strict
• nw.from_native raises a DeprecationWarning if strict is passed, whereas nw.stable.v1 doesn't

[MarcoGorelli]

working on this,