UDBScript: fixed an issue where the Thing's class getSector method did not return null when the thing was not in a sector. Fixes #897

Added action to change the index of linedefs, things, sectors, and vertices. Can be accessed through a shortcut (not bound by default) or the menu of the respective mode (#903)

- A new "Show Textures" option up on the top bar, which draws any sector not flagged to be hidden on the textured automap
- Holding Shift will highlight sectors instead of lines
- Left-clicking on a highlighted sector will toggle the "Not shown on textured automap" flag
- Textures will be shown when Shift is held down even if the "Show Textures" toggle is off

Edit Selection Mode: fixed a problem where floor and ceiling textures were unintentionally scaled in UDMF when resizing the selection. Fixes #873

Nodes Viewer Mode: fixed a problem where trying to engage the mode with an empty map could crash. Fixes #857

Map Analysis Mode: fixed a problem where lines with fractional vertex positions could erroneously be reported as overlapping

Stair Sector Builder Mode: fixed an issue where the number of sectors and the sector depth was not loaded correctly when a default prefab was set. Fixes #847

Nodes Viewer Mode: a crash that could happen when the nodes header was interpreted as an UTF-8 value should be fixed for good now (#827)

UDBScript: setting an UDMF string field to an empty string will not remove the field anymore, but actually set it to an empty string

Disabled visual sloping for game configurations that do not support plane equation slopes. Fixes #828
Added toasts for visual sloping events

Improved UDBScript to version 5:

- Added Plane class
- Added BlockMap, BlockEntry, and BlackMapQueryResult classes
- Sector class
  - Added getLabelPositions method to get the position of sector labels (where tags, effects etc. are displayed)
- Added support for JavaScript BigInt for UDMF fields. This means it's not necessary anymore to use UniValue to assign integers to new UDMF fields. Instead it can be done like this: sector.fields.my_int_field = 1n;
- Added type information file (udbscript.d.ts)

Behavior can be configured in the "Toasts" tab in the preferences.

3D Floor Mode: added support for UDMF game configurations without support for sectors with multiple tags (i.e. Zandronum)

Tag Range plugin: fixed a problem where the new tags were not displayed in Sectors Mode when selection numbering was disabled. Fixes #795

Sectors Mode: fixed a regression where sector labels were not updated after editing sectors. Fixes #793

Fixed a regression where editing map elements did not preserve the selection order, but used the index order instead. Fixes #791

- editing a highlighted, not selected map element will deselect other selected map elements, then start editing the highlighted map element
- dragging a highlighted, not selected map element will deselect other selected map elements, then start dragging the highlighted map element
- dragging a single map element will keep its selection state. I.e. dragging a selected map element will not deselect it after dragging anymore
  - dragging a highlighted, not selected thing will not select it after dragging
- dragging a highlighted, not selected sector, while other sectors are selected, will only drag the highlighted sector, and not the selected sector (and deselect the selected sectors)

Linedefs Mode: fixed a problem where the "Select Single-sided only" and "Select Double-sided only" actions would still display the selection numbers of deselected linedefs

- Sector Color Picker: fixed a problem where the dialog could not be closed using the "enter" or "ESC" buttons
- Light/Sector Color Picker: fixed a problem where closing the dialog would result in a flicker
- Light Color Picker: fixed a problem where canceling the dialog would not revert the color settings

Sound Environment Mode: fixed an issue that caused building sound environments to fail when the arguments of the Sound Environment thing had unexpected values.

Sound Environment Mode: fixed a crash that happened when exiting Draw Lines Mode with the "edit" action and returning to Sound Environment Mode. Fixes #755

Things: fixed an issue where inserting a new thing would not immediately apply ZScript user variables

Visplane Explorer Mode: fixed an issue that caused a crash when the map doesn't have nodes the Visplane Explorer Mode understands. Fixes #736

Visual Mode: fixed an issue where using the "apply camera rotation to things" action did not update the thing cages properly