Maps related to column families in database are extracted
to a column_families_data class. Access to them is possible only
through methods. All methods which may preempt hold rwlock
in relevant mode, so that the iterators can't become invalid.
Fixes: #13290Closes#13349
* github.com:scylladb/scylladb:
replica: make tables_metadata's attributes private
replica: add methods to get a filtered copy of tables map
replica: add methods to check if given table exists
replica: add methods to get table or table id
replica: api: return table_id instead of const table_id&
replica: iterate safely over tables related maps
replica: pass tables_metadata to phased_barrier_top_10_counts
replica: add methods to safely add and remove table
replica: wrap column families related maps into tables_metadata
replica: futurize database::add_column_family and database::remove
4a02865ea1