Fix dialog deleting fullwidth characters

[tompng]

Reline's dialog will delete fullwidth characters and fails to restore it in reset_dialog. This pull request fixes this.

In reset_dialog, what we want for Reline::Unicode.take_range('一二三', 1, 4) could be

• 一二三 string covers range, needed for rerender bottom, rerender top in reset_dialog
• 二三 rerender right in reset_dialog
• 一二 render left in reset_dialog
• 二 string inside range
• ▫️二▫️ string inside range with padding

Changes

take_range will also return position(col and width)

take_range('一二三', 1, 4) #=> ['二', 2, 2]
need to determine where to render the string.
二 should be rendered at col: 2, width: 2, not at col: 1, width: 4

add an option cover_begin, cover_end to take_range

take_range('一二三', 1, 4, cover_begin: true) #=> ['一二', 0, 4] for render left
take_range('一二三', 1, 4, cover_end: true) #=> ['二三', 2, 4] for render right

add an option padding to take_range

Delete padding_space_with_escape_sequences that only adds spaces at the end of the string.
take_range will properly add spaces around the string.
take_range('一二三', 1, 4, padding: true) #=> ['▫️二▫️', 1, 4]
take_range('一二三', 1, 8, padding: true) #=> ['▫️二三▫️▫️▫️', 1, 8]

Refactored reset_dialog

To make the main change easier, I reduced if branches of render top, left, right and bottom.
This change will fix a potentially-bug in rerender left

• old_dialog.column is used where it should be dialog.column
• sign on ydiff looks wrong, compared to rerender right
• dialog.column usually don't move right, ydiff is usually zero, so it's hard to write failing test

Fixed inconsistency of take_range and calculate_width with special charactors \1 and \2

I Added some take_range tests for newly added option and regression test for escape sequence.
Found \1 and \2 is disappeared that will causes inconsistency of calculate_width and take_range.
calculate_width(take_range("a\1xxxxxxxx\2b", 0, 2), true) should be <=2, got 10
This might solve the root cause of #465 (I'm not sure, I cannot reproduce it).

Limitations

This pull request has a limitation. After document dialog is closed, right side of the completion dialog corrupts if there is full-width character between these dialogs.

Clearing dialog depends on adjacent dialog positions, and to fix this, dialog rendering and clearing algorithm might need update.

# change clear_each_dialog to use remaining dialog positions
def clear_each_dialog(dialog_to_be_cleared, remaining_dialog_positions)
  # Carefully clear the dialog
end

# or clear multiple dialogs at once
def clear_dialogs(dialogs_to_be_cleared, remaining_dialog_positions)
  # Check all dialogs and collect all ranges to be cleared
  # Clear each calculated ranges
  # In this approach, we might be able to clear trailing spaces created by clear_each_dialog
end

# or just make a space between correction dialog and document dialog

[tompng]

I will close this because this pull request is incomplete (see Limitations section) and I opend #492 that solves it