Open Editor index or patch search iteration method

[robobenklein]

During an update we need to search through the open editors, ideally in spatial order, need to figure out methods for next child / next of parent / index of self, etc within the layout structures.

Could be related to the grid layout method linked in #12

Will need to support all iterations for the different opening modes of CR added in https://github.com/utk-se/CodeRibbon/pull/87/files#diff-7ae45ad102eab3b6d7e7896acd08c427a9b25b346470d7bc6507b6481575d519