Add support for aliases

[dansherpa]

It doesn't seem that field name aliases are supported? For example, if my avro definition has a field defined as:

{
         "name": "plain_field",
         "type": [
           "null",
           "double"
         ],
         "doc": "Any field",
         "default": null,
         "aliases": [
           "alias_for_that_field"
         ]
}

the resulting class does have a getPlainField() but does not have a getAliasForThatField() method.

[eikemeier]

the resulting class does have a getPlainField() but does not have a getAliasForThatField() method.

That is not how aliases work. It accepts incoming data that has a field alias_for_that_field instead of plain_field.