Sketcher: Add a "close corner" tool that trims/extends one/both lines as required to result in coincident corner projected in extension of both lines

This is request for a new sketcher tool, "close corner", that would trim or extend one or both lines as required to result in coincident corner projected in extension of both lines.
It would be equivalent to Fillet tool with default radius "0" and no creation of the fillet arc.
It would replace consecutive use of trim extend tools combination with an important feature to preserve graphical elements of the original lines, such as angle and position, regardless of the constraint status of those lines.

Start by examining the Sketcher Fillet, trim, and extend tools referenced in the request. Define the close-corner behavior for one or both lines, including trimming or extension and preservation of the original lines' angle and position; done means the tool creates a coincident corner without a fillet arc.

Written by the indexing model from the issue text.