sql: pass true types of columns to Tarantool

As a main part of introducing strict typing in SQL it is required to
prohibit typeless columns in parser's grammar. Originally, SQLite simply
assigns typeless columns to BLOB affinity. Moreover, due to historical
reasons, all columns were stored with <SCALAR> type in Tarantool core
(except for <INTEGER> when it comes to primary key).  Column type should
be defined on table creation. Allowed data types are: <TEXT>, <VARCHAR>,
<CHAR>, <BLOB>, <INT[EGER]>, <REAL>, <FLOAT>, <NUMERIC>, <DECIMAL>,
<DOUBLE> <DATE> and <DATETIME>. However, still any declared data type is
converted to one of <BLOB>, <TEXT>, <REAL> or <INTEGER> affinities.
While affinity reaches space format, it is (again) converted to
Tarantool's field type. To be more precise, table of conversions:

+----------+----------+------------+
| SQL TYPE | AFFINITY | FIELD TYPE |
+----------+----------+------------+
| FLOAT    | REAL     | NUMBER     |
| REAL     | REAL     | NUMBER     |
| DOUBLE   | REAL     | NUMBER     |
| NUMERIC  | REAL     | NUMBER     |
| DECIMAL  | REAL     | NUMBER     |
| INTEGER  | INTEGER  | INTEGER    |
| TEXT     | TEXT     | STRING     |
| VARCHAR  | TEXT     | STRING     |
| CHAR     | TEXT     | STRING     |
| BLOB     | BLOB     | SCALAR     |
| DATETIME | REAL     | NUMBER     |
| DATE     | REAL     | NUMBER     |
| TIME     | REAL     | NUMBER     |
+----------+----------+------------+

<VARCHAR> and <CHAR> types should be specified with length
(e.g. name VARCHAR(10)), but this length currently is not used when
types are processed. Only purpose is to support ANSI syntax.
The same for <NUMERIC> and <DECIMAL> - it is allowed to specify scale
and precision, but they don't affect the way they are stored in memory.

Note that patch is not self-sufficient: a lot of tests still fail due to
wrong types conversions. Fix for that comes as next two patches.

Closes #3018
Closes #3104
Closes #2494
Closes #3459