Seems dump tool don't support annotations on Functions

[2011aad]

Describe the bug

A clear and concise description of what the bug is.
When using dump tool to translate an ast into thrift files, annotations of functions will disappear in dumped file.
func DumpIDL(ast *parser.Thrift) (string, error)

To Reproduce

Steps to reproduce the behavior:

1. in tool/trimmer/test_cases/sample1.thrift, append (api.get="/hello") at the end of line 127
2. Run TestDumpSingle in tool/trimmer/dump/dump_test.go
3. the output of DumpIDL function do not have (api.get="/hello")

Expected behavior

Expect (api.get="/hello") appears in the output of DumpIDL function.

Screenshots

Suggestion
It seems that the FunctionTemplate missing the annotation part. Add the following line of code seems work fine.

const FunctionTemplate =
{{define "Function"}}
{{- if .ReservedComments}}{{" "}}{{- ReplaceQuotes .ReservedComments -}}{{"\n"}}{{end -}}
{{" "}}{{if .Oneway}}oneway {{end}}{{template "Type" .FunctionType}} {{.Name}}(
{{- range $index, $element := .Arguments}}
{{- if $index}}, {{end -}}{{- template "SingleLineField" .}}
{{- end}})
{{- if .Throws}}
{{- "throws" }} (
{{- range $index, $element := .Throws}}
{{- if $index}},{{end -}}{{- template "SingleLineField" .}}
{{- end}})
{{- end}}
{{- template "Annotations" .Annotations -}}
{{- end -}}
``

[HeyJavaBean]

Thanks for feedback.