Set EastAsianWidth to fix broken layout

[egawata]

Box layout in the top of screen is broken when using CJK locales.

The following is a screenshot, using MacOS 12.4, iTerm2 3.4.16, and LANG=ja_JP.UTF-8

The first letter of titles aren't displayed, and box layout is broken.

The reason is that those box-drawing characters are ambiguous width ones, which will be displayed with a narrow width with non-CJK locales, but with wide width with CJK, which would break layout. One way to fix it is to override DefaultCondition.EastAsianWidth variable in go-runewidth with false, so that any ambiguous width charactes would always be displayed with narrow width.

[sachaos]

Sorry for late. I'll check soon.