tt connect interactive console: expanded formatting modes

[TarantoolBot]

Product: tt CLI
Since: ?
Audience/target: all
Root document: ? https://www.tarantool.io/en/doc/latest/reference/tooling/interactive_console/
? https://www.tarantool.io/en/doc/latest/reference/tooling/tt_cli/connect/
SME: @ GRISHNOV

Details

The patchset introduces addition commands for the tt connect console.

It adds several common commands that relate to a general functionality:

• \help, ? - to show help message with additional information and
  a list of all commands.
• \quit, \q - quit from the console. Previously this command worked
  on the tarantool side, but now it works on the tt side and does
  not require execution rights for a user.

In addition, the patch adds commands for extended output modes:

• \set output <format> - set format lua, table, ttable or
  yaml (default)
• \set table_format <format> - set table format default, jira
  or markdown
• \set graphics <false/true> - disables/enables (default)
  pseudographics for table modes
• \set table_column_width <width> - set max column width for
  table/ttable
• \xw <width> - set max column width for table/ttable
• \x - switches output format cyclically
• \x[l,t,T,y] - set output format lua, table, ttable or yaml
• \x[g,G] - disables/enables pseudographics for table modes

Supported formats:

1. yaml - shows data as a YAML document. The format is
   used now by tarantool and tt.
2. lua - shows data as Lua-compatible structs.
3. table - shows data as a pseudo graphical table.
4. ttable - the same as the table format, but a result table is
   transposed (rotate data from rows to columns).

Supported table formats (for table or ttable formats):

1. default - shows data as a pseudo graphical table.
2. markdown - shows data as a Markdown-compatible table.
3. jira - shows data as a Jira-compatible table.

Example:

> \set output table
> box.space.customers:select()
+------+-----------+------+
| col1 | col2      | col3 |
+------+-----------+------+
| 1    | Elizabeth | 12   |
+------+-----------+------+
> \xg
> box.space.customers:select()
 col1  col2       col3
 1     Elizabeth  12
 2     Mary       46
 3     David      33

Requested by @GRISHNOV in tarantool/tt@5189d4f.

Definition of done

• Define the relation between tt console and tarantool console to find the proper place for this doc
• Describe the new formatting capabilities in the console documentation