[ticket/10910] Allow setting size selects in build_cfg_template()

PHPBB3-10910
[ticket/10910] Add unit tests for select

PHPBB3-10910
[ticket/10910] Fix unit tests

PHPBB3-10910
[ticket/10910] Do not add size when its 1 (default)

PHPBB3-10910
Merge pull request #1887 from nickvergessen/ticket/skouat/10910

[ticket/10910] Function build_cfg_template() allow $size for $tpl_type = select