fix(pilota-thrift-parser): adapt the thrift annotation syntax

[Ggiggle]

Motivation

The annotation syntax is not defined in the official web. As there are existing idls, we should try best to be compatible with them.

Solution

We allow the annotations syntax below:

AnnotationList ::= Annotation (ListSeparator Annotation)* ListSeparator?
Annotation ::= Identifier "=" Literal
ListSeparator ::= "," | ";"

// For example.

(
            cpp.type = "DenseFoo",
            python.type ="DenseFoo", 
            go.type ="DenseFoo";
            java.final=""
        )