Parse triple quoted string annotations as if parenthesized (#15387)

## Summary

Resolves #9467 

Parse quoted annotations as if the string content is inside parenthesis.
With this logic `x` and `y` in this example are equal:

```python
y: """
   int |
   str
"""

z: """(
    int |
    str
)
"""
```

Also this rule only applies to triple
quotes([link](https://github.com/python/typing-council/issues/9#issuecomment-1890808610)).

This PR is based on the
[comments](https://github.com/astral-sh/ruff/issues/9467#issuecomment-2579180991)
on the issue.

I did one extra change, since we don't want any indentation tokens I am
setting the `State::Other` as the initial state of the Lexer.

Remaining work:

- [x] Add a test case for red-knot.
- [x] Add more tests.

## Test Plan

Added a test which previously failed because quoted annotation contained
indentation.
Added an mdtest for red-knot.
Updated previous test.

Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
Co-authored-by: Micha Reiser <micha@reiser.io>

crates/red_knot_python_semantic/resources/mdtest/annotations/string.md

@@ -173,3 +173,40 @@ p: "call()"
 r: "[1, 2]"
 s: "(1, 2)"
 ```
+
+## Multi line annotation
+
+Quoted type annotations should be parsed as if surrounded by parentheses.
+
+```py
+def valid(
+    a1: """(
+      int |
+      str
+  )
+  """,
+    a2: """
+     int |
+       str
+  """,
+):
+    reveal_type(a1)  # revealed: int | str
+    reveal_type(a2)  # revealed: int | str
+
+def invalid(
+    # error: [invalid-syntax-in-forward-annotation]
+    a1: """
+  int |
+str)
+""",
+    # error: [invalid-syntax-in-forward-annotation]
+    a2: """
+  int) |
+str
+""",
+    # error: [invalid-syntax-in-forward-annotation]
+    a3: """
+      (int)) """,
+):
+    pass
+```