* #74 - Integration with Bookmarks core plugin and support for indirect drag & drop arrangement
- added new plugin setting to enable auto-integration with bookmarks
- full integration with standard sorting at folder level and at sorting group level
- refined support for implicit sorting for bookmarks plugin integration
- documentation update (partial, sketchy)
- context menu for 'bookmark this' and 'bookmark+siblings' for sorting
- order of bookmarked siblings reflects the current sorting in File Explorer, whatever it is (!!!)
- handler for 'changed' event of the vault to reflect files/folders locations change in the bookmarks automatically, whenever applicable
- adjusted behavior of by-bookmark-comparator to adhere to the multi-level sorting support implemented in #89 and merged recently to this branch. Basically, each comparator is responsible only for its own comparison and should no fallback into other default comparisons - instead it should return 0, which indicates item which are equal from the perspective of the comparator
- adjusted bookmarks integration to the merged from master multi-level sorting support and its implications
- fix suggested by github code check
- advanced performance optimizations: bookmarks cache finetuning, switching to Obsidian sort code if the implicit bookmark-integration sorting spec is in effect for a folder and there are no bookmarked items in the folder
- update of treatment of whitespace in parent path extraction: spaces allowed as leading/trailing in path elements
- increased coverage of the new functionality with unit tests
- basic manual tests done
- next step: real-life usage tests
- the meaning of CustomSortOrder.standardObsidian changes from a fixed one to what is actually selected in Obsidian UI
- the CustomSortOrder.standardObsidian can be applied at a folder level (as the default for folder) and at a group level (this is a major addition)
- added a mapping of Obsidian UI sorting methods onto internal plugin sorting methods, plus addition of the Obsidian UI logic to push folders to the top unconditionally
- !!! NO NEW UNIT TESTS FOR THIS FEATURE - must add later
- not tested manually, as the commits extraction and pushing is done as part of #88 github issue
- new keyword added to support items starred with Obsidian core plugin 'Starred'
- the keyword is `starred:`
- detection and more user friendly handling of the general error condition when the File Explorer is not available
- new ribbon status icon shape to indicate the general error plus detailed error logged to the console