feat(tests): Add shiny.pytest, shiny.run and shiny.playwright

[karangattu]

Fixes #1156

While more documentation will be needed, this will be done in a followup PR. If docs are not met, we can cripple the exposed classes / methods then before release.

---

Public API being exposed:

• shiny
  • pytest
    • create_app_fixture()
    • ScopeName; Fixture levels for scope within pytest (not exposed)
    • _pytest.py
      • local_app fixture. Autoloaded via pytest11 entrypoint described in setup.cfg
  • run
    • run_shiny_app() -> ShinyAppProc: Run shiny app process
    • ShinyAppProc: Shiny app process class. Context Manager that calls .close() on __exit__().
  • playwright
    • expect
      • expect_to_change(); Wait until a Locator has updated
      • expect_attribute_to_have_value()
      • expect_to_have_class();
      • expect_not_to_have_class();
      • expect_to_have_style();
    • controls
      • shiny.playwright.controls classes. (Click to expand!)

        • InputActionButton
        • InputActionLink
        • InputCheckbox
        • InputCheckboxGroup
        • InputDarkMode
        • InputDate
        • InputDateRange
        • InputFile
        • InputNumeric
        • InputPassword
        • InputRadioButtons
        • InputSelect
        • InputSelectize
        • InputSlider
        • InputSliderRange
        • InputSwitch
        • InputTaskButton
        • InputText
        • InputTextArea
        • OutputCode
        • OutputDataFrame
        • OutputImage
        • OutputPlot
        • OutputTable
        • OutputText
        • OutputTextVerbatim
        • OutputUi
        • ValueBox
        • Card
        • Accordion
        • Sidebar
        • Popover
        • Tooltip
        • NavItem
        • NavsetBar
        • NavsetCardPill
        • NavsetCardTab
        • NavsetCardUnderline
        • NavsetHidden
        • NavsetPill
        • NavsetPillList
        • NavsetTab
        • NavsetUnderline
        • DownloadButton
        • DownloadLink

---

Typical typed usage:

from playwright.sync_api import Page

from shiny.playwright.controls import Accordion, InputActionButton, OutputTextVerbatim
from shiny.run import ShinyAppProc

Typical untyped usage:

from shiny.playwright.controls import Accordion, InputActionButton, OutputTextVerbatim

[schloerke]

Forgot to add a change log entry