TemplateString: Proper inference similar to JoinedStr._infer and additional tests for the as_string()

[jacobtylerwalls]

Fix this error in pylint with 3.14:

• AttributeError: 'TreeRebuilder' object has no attribute 'visit_templatestr'

https://docs.python.org/3.14/library/ast.html#ast.TemplateStr

[cdce8p]

Initial support added in #2793 and released as part of 4.0.0b2.

Open issues

• Additional tests for the as_string() logic. The basics work but there might be a lot of edge case which need to be handled properly. The existing f-string tests could provide a good starting point.
  

  astroid/tests/test_nodes.py

  Lines 295 to 307 in f9e109e

  	def test_f_strings(self):
  	code = r'''
  	a = f"{'a'}"
  	b = f'{{b}}'
  	c = f""" "{'c'}" """
  	d = f'{d!r} {d!s} {d!a}'
  	e = f'{e:.3}'
  	f = f'{f:{x}.{y}}'
  	n = f'\n'
  	everything = f""" " \' \r \t \\ {{ }} {'x' + x!r:a} {["'"]!s:{a}}"""
  	'''
  	ast = abuilder.string_build(code)
  	self.assertEqual(ast.as_string().strip(), code.strip())

• Add proper inference similar to JoinedStr._infer.
  

  astroid/astroid/nodes/node_classes.py

  Lines 4775 to 4781 in f9e109e

  	def _infer(
  	self, context: InferenceContext | None = None, **kwargs: Any
  	) -> Generator[InferenceResult, None, InferenceErrorInfo | None]:
  	if self.values:
  	yield from self._infer_with_values(context)
  	else:
  	yield Const("")