gh-134551: Add t-strings support to pprint

[loic-simon]

Handle formatting of Template and Interpolation types in pprint functions:

>>> from pprint import pp
>>> name = "World"
>>> pp(t"Hello {World}")
Template(strings=('Hello ', ''),
         interpolations=(Interpolation('World', 'name', None, ''),))""")

Very straightforward, using existing PrettyPrinter helper methods.

To avoid slowing import time, I did not import Template and Interpolation from string.templatelib, but instead copied their (very simple) definition:

cpython/Lib/string/templatelib.py

Lines 8 to 11 in 99a9ab1

	t = t"{0}"
	Template = type(t)
	Interpolation = type(t.interpolations[0])
	del t

• Issue: Add support for Template type (t-strings) to pprint #134551

[loic-simon]

Not sure why test.test_tokenize.TestRoundtrip.test_random_files fails on test_pprint.py? If I replace t-strings by f-strings it pass, is it an issue with the test not handling t-strings? Or a real issue with tokenizer round-trippring and t-strings?

Edit: looks like a real problem, I have a MRE, opening an issue soon