Add annotation support

[jlamberts-yobi]

Adds support for most annotations. For our use case, we actually really just need field-level annotations, but I took a look at the issues and saw others were interested in broader annotations in #278, so figured I'd include those as well.

Specifically:

• Struct-level annotations get a __thrift_annotations__ attr, with struct field annotations under the __thrift_field_annotations__ attr
• Enum-level annotations get a __thrift_annotations__ attr, with item annotations under __thrift_item_annotations__
• Service-level annotations get a __thrift_annotations__ attr, with function annotations under __thrift_function_annotations__
• The top-level module gets lazy typedef alias and const annotations under __thrift_typedef_annotations__ and __thrift_const_annotations__, respectively

Note that this PR does not add support for annotations on the types, mostly because that would touch a lot more code: since types are represented by ints, we can't easily add metadata (like annotations).

So we parse the "foo=bar" annotation, but not the unicode.encoding annotation in typedef string ( unicode.encoding = "UTF-16" ) non_latin_string (foo="bar").

[aisk]

Hi @jlamberts-yobi, thank you for your contribution. This feature and the code quality look very good at first glance.

However, I’m quite busy these days, so I can’t finish the review right now. I plan to complete it this weekend or early next week, so please be patient.

And let’s also see the review comments from other people during this period.

[jlamberts-yobi]

Hi @jlamberts-yobi, thank you for your contribution. This feature and the code quality look very good at first glance.

However, I’m quite busy these days, so I can’t finish the review right now. I plan to complete it this weekend or early next week, so please be patient.

And let’s also see the review comments from other people during this period.

Awesome, sounds good!

[jlamberts-yobi]

Hi @jlamberts-yobi, thank you for your contribution. This feature and the code quality look very good at first glance.

However, I’m quite busy these days, so I can’t finish the review right now. I plan to complete it this weekend or early next week, so please be patient.

And let’s also see the review comments from other people during this period.

Hey @aisk , just following up to see if you had any other thoughts or feedback on this change.

[cocolato]

Thanks! LGTM.