Improved associations between arbitrary UDMF fields (used by the Eternity Engine game configuration)

* Updated the bundled Zandronum ACC with Zan 3.1 changes

* Add Zandronum 3.1 functions and constants to its ACS configuration

* Updated the Zandronum ACC (again), as it was missing GAMESTATE definitions

UDBScript: the methods of the Pen class now return the instance of the Pen class to allow method chaining. Resolves #662

Hexen Game Configuration: fixed a problem where the default arguments of the Death Wyvern had special names, even though they actually don't do anything in game. Also renamed the thing from "Dragon Lich" to the correct "Death Wyvern". Fixes #660

Added map scripting capabilities to UDB (#656). Documentation at https://biwa.github.io/udbscript-docs/

(G)ZDoom game configuration: added several missing UDMF fields for linedefs and sectors, so that they show up in the custom tab. Fixes #628

Eternity Engine game configuration: it's again possible to set the floor and ceiling brightness independently from the sector brightness

Game configurations: added option to enable/disable GZDoom style distinct brightness for walls/ceilings/floors. Fixes #618

Eternity Engine game configuration: fixed a problem where the Friendly and Dormant flags were not correctly pasted in Doom format.

Eternity Engine game configuration: fixed a problem where the 3DMidTex flag was not correctly pasted in Doom format. Fixes #606

Eternity Engine game configurations: added support for arbitrary map names in the default testing parameters

Boom game configuration: fixed a problem where linedef actions 264 and 265 were not labeled correctly

Negative vertical patch offsets are now handled correctly based on the game configuration. Fixes #561

Added fixes for the stuck thing checker for the Eternity Engine configuration (thanks for hawkwind3). Fixes #551

Map Analysis Mode: fixed a problem where checking for stuck things works incorrectly in some situations (thanks to hawkwind3). Fixes #469

https://doomwiki.org/wiki/Static_limits

The VPO limit is raised by Hexen (160) & Strife (200)
so make it configurable in the basegame.

The hover tooltip will reflect the adjusted max
limit and the heatmap is interpolated to 0-255
for the 256x10 visplane_pal.png colour range
gradient.

Boom's linedef special 260 allows a 64K
translucency lump to be applied to the
front sidedef's midtex for applying a
custom 1 to 99% translucency value. Stop
reporting this as an unknown texture.

Updated ZDaemon ACS configuration (thanks to DoomKrawa)

Several new ZDaemon ACS function added (thanks to DoomKrawa).

Map Analysis Mode: checking for missing activation flags (UDMF) now finds linedef that are missing an actual activation flag, not only lines without any flags in that group. Fixes #288
Linedef Editing Form (UDMF): now only missing required activation flags are marked red

Added support for only enabling editing modes when the current game configuration supports the features. Currently only applies to 3D Floor Mode, Slope Mode, and Draw Slope Mode. Fixes #463

Eternity Engine configuration: moved portal related sector flags to the portals tab of the sector edit form

Error Checker: added config options to ignore unknown textures on sidedefs for certain actions. Resolves #518