Get a top 10 of biggest checkouts in repository

[ymartin59]

When migrating repository (from Subversion for instance), it may happen some branches or tags introduce mistakes and Git repository has multiple big checkouts I am interested to identify in a single list (so that they can be excluded from migration process in my case).

So I am interested in reusing git-sizer "biggest checkouts" calculation to report the "top X" biggest checkouts with specific argument.