DRAFT: Code formatting using spotless in Phoenix

[NihalJain]

This PR currently has 3 commits, each of which do independent tasks as follows:

• Add spotless plugin to format code in phoenix
  • Update dev/PhoenixCodeTemplate.xml to use latest format as in hbase.
    • Question to reviewers: Also IMO we should rename this file to phoenix_eclipse_formatter.xml?
  • Fix file having misplaced package block as we do not want any manual code change in next commit where we run spotless
  • Copied licnese-header from hbase, the one which phoenix was using was a little different
  • Question to reviewers: Revisit the import order rules?
• Run spotless:apply to format code in phoenix:
  • No manual code change in this commit
• Add spotless phoenix pre commit check

We could create 3 JIRA sub tasks and do each commit one at a time for ease of backporting.

TODO: Raise JIRAs as needed