Rename methods to match JMAP names

[mmcclimon]

I'm not sure why we decided not to do this when we did the big renaming. This commit changes the method names (and their hooks) to better match the JMAP verbs to which they correspond. That entails this set of changes:

• get_updates is now changes (and related, so ix_get_updates_check is now ix_changes_check)

• get_list_updates is now query_changes (and so, ix_query_changes_check)

• get_list is now query. This was the biggest change, only because there are a bunch of auxiliary methods used for querying. These methods are now called ix_query_enabled, ix_query_check, ix_query_filter_map, ix_query_sort_map, and ix_query_joins.

This also changes the name of the tests so that they still make sense: updates.t is now changes.t, and get_foo_list.t is now query.t.

[wolfsage]

Seems good! Dependent projects will need changes of course