The preview had an off by one error in case colors where deactivated
and did not take fullwidth unicode characters into account when
displaying the preview.

This improves the current history search feature by adding substring
based history search similar to ZSH. In case the `UP` or `DOWN`
buttons are pressed after writing a few characters, the start string
up to the current cursor is used to search the history.

All other history features work exactly as they used to.

Fixes: nodejs#28437

Skip history entries that are identical to the currently visible line
to improve the user experience.

Reaching the history end caused the last entry to be persistent.
That way there's no actualy feedback to the user that the history
end is reached. Instead, visualize the original input line and keep
the history index at the history end in case the user wants to go
back again.

Simplify getStringWidth by removing dead code (the options were
unused) and by refactoring the logic.

This moves the charLengthLeft() and charLengthAt() into the internal
readline file. This allows sharing the functions internally with
other code.

This improves the performance in GetColumnWidth for full width
characters.

The option is now set to true by default. Most terminals do not have
full emoji support and visualize emojis with zero width joiners as
individual emojis.
Also verify that at least one argument is always passed through to the
function and remove support for passing through code points. Only
accept strings from now on to simplify the API.

Fixes: nodejs#25272

This improves the completion previews by activating them for lines
that exceed the current terminal columns.
As a drive-by fix it also simplifies some statements.

This also adds a test to verify that changed writer options also
change the preview output depending on the options.

readline: improve getStringWidth on non-Intl builds

The getStringWidth function returned the wrong width for multiple
inputs. It's now improved by supporting various zero width characters
and more full width characters.