[cookies] Make browser names case insensitive

yt_dlp/__init__.py

@@ -248,7 +248,7 @@ def parse_retries(retries, name=''):
     if opts.cookiesfrombrowser is not None:
         opts.cookiesfrombrowser = [
             part.strip() or None for part in opts.cookiesfrombrowser.split(':', 1)]
-        if opts.cookiesfrombrowser[0] not in SUPPORTED_BROWSERS:
+        if opts.cookiesfrombrowser[0].lower() not in SUPPORTED_BROWSERS:
             parser.error('unsupported browser specified for cookies')
 
     if opts.date is not None:

yt_dlp/cookies.py

@@ -748,6 +748,7 @@ def _is_path(value):
 
 
 def _parse_browser_specification(browser_name, profile=None):
+    browser_name = browser_name.lower()
     if browser_name not in SUPPORTED_BROWSERS:
         raise ValueError(f'unsupported browser: "{browser_name}"')
     if profile is not None and _is_path(profile):

yt_dlp/options.py

@@ -1128,7 +1128,7 @@ def _dict_from_options_callback(
             'You can specify the user profile name or directory using '
             '"BROWSER:PROFILE_NAME" or "BROWSER:PROFILE_PATH". '
             'If no profile is given, the most recently accessed one is used'.format(
-                '|'.join(sorted(SUPPORTED_BROWSERS)))))
+                ', '.join(sorted(SUPPORTED_BROWSERS)))))
     filesystem.add_option(
         '--no-cookies-from-browser',
         action='store_const', const=None, dest='cookiesfrombrowser',