Move 'where' to parser keywords; Add 'filter' command (#7365)

# Description

This PR moves the `where` command to a parser keyword. While it still
uses the shape-directed parsing dictated by the signature, we're free to
change the parsing code now to a custom one once we remove the syntax
shapes.

As a side effect, the `where -b` flag was removed and its functionality
has moved to the new `filter` command.

Just FYI, other commands that take row conditions:
- `take until`
- `take while`
- `skip until`
- `skip while`
- `any`
- `all`

We can either move these to the parser as well or make them accept a
closure instead of row condition.

# User-Facing Changes

New `filter` command which replaces `where -b` functionality.

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-protocol/src/shell_error.rs

@@ -814,6 +814,19 @@ Either make sure {0} is a string, or add a 'to_string' entry for it in ENV_CONVE
         #[label = "'{0}' is deprecated. Please use '{1}' instead."] Span,
     ),
 
+    /// Attempted to use a deprecated parameter.
+    ///
+    /// ## Resolution
+    ///
+    /// Check the help for the command and update your script accordingly.
+    #[error("Deprecated parameter {0}")]
+    #[diagnostic(code(nu::shell::deprecated_command), url(docsrs))]
+    DeprecatedParameter(
+        String,
+        String,
+        #[label = "Parameter '{0}' is deprecated. Please use '{1}' instead."] Span,
+    ),
+
     /// Non-Unicode input received.
     ///
     /// ## Resolution