Support trailing commas in FROM clause

[barsela1]

support trailing commas in FROM clause.

• add a const global list of keyworads that are allowed to appear after FROM, called "ALLOWED_KEYWORD_AFTER_FROM"
• Every dialict implement:
  --get_reserved_keyword_after_from function that returns ALLOWED_KEYWORD_AFTER_FROM as default. each dialect can customize the list if needed.
  -- supports_from_trailing_commas function that returns false as default but for each dialect that supports trailing commas in the FROM clause can customize the return value to true (e.g., Snowflake).
• add a function "parse_from" to handle the FROM keyword. parse_from set and pass trailing_commas according to the return value of self.dialect.supports_from_trailing_commas().
• change signature of parse_comma_separated_with_trailing_commas and is_parse_comma_separated_end_with_trailing_commas by adding parameter "reserved_keywords" (&[Keyword])
  -at is_parse_comma_separated_end_with_trailing_commas: keywords::RESERVED_FOR_COLUMN_ALIAS.contains(&kw.keyword) replaced by reserved_keywords so that the reserved_keywords can be determined by the current parsing state.
• In other cases where is_parse_comma_separated_end_with_trailing_commas is used, keywords::RESERVED_FOR_COLUMN_ALIAS can be obtained by calling the default_reserved_keywords function and passing it through the reserved_keywords parameter.

tests:
-added new tests.
-all tests passed.

[iffyio]

Thanks @barsela1! The changes look reasonable to me overall, left some comments

[iffyio]

LGTM! Thanks @barsela1!
cc @alamb

[iffyio]

@barsela1 could you take a look to resolve the conflicts on the branch?

[alamb]

I also restarted the checks

[alamb]

Thanks @barsela1 and @iffyio ❤️