Review PostgreSQL extensions

[microamp]

Based on the latest snapshot, the database has the following extensions.

\dx

                                            List of installed extensions
        Name        | Version |   Schema   |                              Description
--------------------+---------+------------+------------------------------------------------------------------------
 adminpack          | 2.1     | pg_catalog | administrative functions for PostgreSQL
 amcheck            | 1.3     | public     | functions for verifying relation integrity
 bloom              | 1.0     | public     | bloom access method - signature file based index
 btree_gin          | 1.3     | public     | support for indexing common datatypes in GIN
 btree_gist         | 1.6     | public     | support for indexing common datatypes in GiST
 citext             | 1.6     | public     | data type for case-insensitive character strings
 fuzzystrmatch      | 1.1     | public     | determine similarities and distance between strings
 pageinspect        | 1.9     | public     | inspect the contents of database pages at a low level
 pg_buffercache     | 1.3     | public     | examine the shared buffer cache
 pg_freespacemap    | 1.2     | public     | examine the free space map (FSM)
 pg_stat_statements | 1.9     | public     | track planning and execution statistics of all SQL statements executed
 pg_trgm            | 1.6     | public     | text similarity measurement and index searching based on trigrams
 pg_visibility      | 1.2     | public     | examine the visibility map (VM) and page-level visibility info
 pgrowlocks         | 1.2     | public     | show row-level locking information
 pgstattuple        | 1.5     | public     | show tuple-level statistics
 plpgsql            | 1.0     | pg_catalog | PL/pgSQL procedural language

Many of them probably aren't being used (anymore). Review and clean up accordingly.