LibreOfficeBase ResultSet metadata issues

[nicktorwald]

Implement several ResultSetMetaData methods to be able be run as a
proper JDBC-driver inside Base tool.

Reworked SQL data types in relation with Tarantool NoSQL types as well
as JDBC types. A data conversations are left out of this commit.

This commit also addresses to tarantool/tarantool#3292 to be executed
in a dry-run mode. LibreOffice Base uses PreparedStatement.getMetadata()
without a real query execution to extract a metadata in advance. This
causes NPE in #198.

Follows on: #198

[coveralls]

Coverage increased (+2.5%) to 74.783% when pulling 05ce89d on nicktorwald/gh-198-libre-office-npe into b53e0ba on master.

[nicktorwald]

Actually, this PR cannot fix NPE issue from #198 because of lack of dry-run mode.

I tested it with a real query execution in PreparedStatement.getMetaData(). When I overcame this NPE I faced several extra issues related to unimplemented ResultSetMetaData methods. As a result, I implemented a few of them to work properly in Base environment. But some of those methods are also blocked by Tarantool DB, I assume, such as nullability flag, auto-increment flag, and, possibly, column name/aliases.

[Totktonada]

<...> blocked by Tarantool DB, I assume, such as nullability flag, auto-increment flag, and, possibly, column name/aliases.

They are available (except aliases) via 'information schema': _vspace view — if I get you right. Don't sure however whether it is possible to match it against a query metadata in a general case. So we need to understand our needs, look around other DBMS protocols / APIs and propose a change for tarantool (file an issue).

[Totktonada]

LGTM in general. Just several minor comments.