Rename Magic* to IpyEscape* (#6395)

## Summary

This PR renames the `MagicCommand` token to `IpyEscapeCommand` token and
`MagicKind` to `IpyEscapeKind` type to better reflect the purpose of the
token and type. Similarly, it renames the AST nodes from `LineMagic` to
`IpyEscapeCommand` prefixed with `Stmt`/`Expr` wherever necessary.

It also makes renames from using `jupyter_magic` to
`ipython_escape_commands` in various function names.

The mode value is still `Mode::Jupyter` because the escape commands are
part of the IPython syntax but the lexing/parsing is done for a Jupyter
notebook.

### Motivation behind the rename:
* IPython codebase defines it as "EscapeCommand" / "Escape Sequences":
* Escape Sequences:
292e3a2345/IPython/core/inputtransformer2.py (L329-L333)
* Escape command:
292e3a2345/IPython/core/inputtransformer2.py (L410-L411)
* The word "magic" is used mainly for the actual magic commands i.e.,
the ones starting with `%`/`%%`
(https://ipython.readthedocs.io/en/stable/interactive/reference.html#magic-command-system).
So, this avoids any confusion between the Magic token (`%`, `%%`) and
the escape command itself.
## Test Plan

* `cargo test` to make sure all renames are done correctly.
* `grep` for `jupyter_escape`/`magic` to make sure all renames are done
correctly.

crates/ruff_python_ast/src/helpers.rs

@@ -108,7 +108,7 @@ where
                 | Expr::Subscript(_)
                 | Expr::Yield(_)
                 | Expr::YieldFrom(_)
-                | Expr::LineMagic(_)
+                | Expr::IpyEscapeCommand(_)
         )
     })
 }
@@ -247,7 +247,7 @@ where
                     .is_some_and(|value| any_over_expr(value, func))
         }
         Expr::Name(_) | Expr::Constant(_) => false,
-        Expr::LineMagic(_) => false,
+        Expr::IpyEscapeCommand(_) => false,
     }
 }
 
@@ -534,7 +534,7 @@ where
         Stmt::Nonlocal(_) => false,
         Stmt::Expr(ast::StmtExpr { value, range: _ }) => any_over_expr(value, func),
         Stmt::Pass(_) | Stmt::Break(_) | Stmt::Continue(_) => false,
-        Stmt::LineMagic(_) => false,
+        Stmt::IpyEscapeCommand(_) => false,
     }
 }