[Go] migrate to new flatbuffers-v1.11.0

[asfimport]

migrating to v1.11.0 improves the generated Go code (better handling of booleans and enums)

Reporter: Sebastien Binet / @sbinet
Assignee: Sebastien Binet / @sbinet

PRs and other links:

• GitHub Pull Request #4228

_{Note: This issue was originally created as ARROW-5233. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Issue resolved by pull request 4228
#4228