Allow custom http header configs depending on the browser

[paveldudka]

Firefox crashes when proxy is in use and chrome headers are specified.
Adding ability to control what kind of headers we want depending on the browser

Looks roughly like this:

async with async_playwright() as playwright, await playwright.firefox.launch(
        headless=False,
    ) as browser:
        context = await browser.new_context( )
        page = await context.new_page()
        await stealth_async(page, config=StealthConfig(browser_type=BrowserType.FIREFOX))
        await page.goto("https://bot.sannysoft.com/")

[TinyGambe]

LGTM