Describe the bug
Currently, the OPs (Operators) have no way to edit the Global Markers found in world/data/aAtlasGlobalMarkers.dat in a graphically friendly interface.

Instead, the choices are either to have a Server Admin edit them individually (by finding each Marker in the .dat file.. a daunting task with what might be several thousand entries) or by deleting all of them.

An Atlas GUI (perhaps with a button from a Atlas only available to OPs or through a Creative gained Atlas) would:

1. Be much easier to see which Global Markers are in the Chunks of concern.
2. Multiple OPs could collaborate on changing Global Markers from in game.

This would allow us to do things such as:
Issue 1. Create Global Markers for Chunks already explored before installing the Atlas mod.
Issue 2. Delete Global Markers that are no longer correct.
Issue 3. Edit existing Global Markers in the Chunks to different Markers.

To Reproduce
Steps to reproduce the behavior as a OPs user:

1. Start a new Server including Electroblob's Wizardry and Ancient Spellcraft mods (without Antique Atlas) and explore several Chunks that contain structures that would have created Global Markers (such as villages, nether portals, wizard towers, battlemage camps, sage hills, etc).
2. Add the Antique Atlas mod and open a new Atlas.
3. The Chunks explored before Antique Atlas was installed are missing any Global Markers.
4. Create the missing Global Markers for the already explored Chunks. (Issue 1)
5. Explore enough Chunks to add a few hundred additional Global Markers.
6. Delete 10 Chunks (perhaps the Server Admin needs to re-create these Chunks to allow for world generation option from nely added mods.. or perhaps the server world size has gotten too large and you need to clear out Chunks that are rarely visited).
7. Delete the Global Markers in the deleted Chunks. (Issue 2)
8. Edit the Global Marker for 10 specific villages where a Librarian can be found from a village Marker to a scroll Marker within a 3 by 3 Chunk area (9 Chunks). (Issue 3)

Expected behavior
As a OPs user, I expected to be able to open a Atlas Map and to be able to create/delete/edit the Global Markers in the GUI interface.

Screenshots
The aAtlasGlobalMarkers.dat is too difficult to edit when it comes to trying to delete or edit specific Global Markers (without a ID to search for):

The Atlas GUI would be a great way for OPs users to edit the Global Markers (or at least see the ID with advanced tooltips turned on):

Version information (please complete the following information):

• AntiqueAtlas: 4.6.3 (latest version)
• Minecraft: 1.12.2
• Forge: 14.23.5.2860 (latest version)
• ElectroblobsWizardry: 4.3.11 (latest version)
• AncientSpellcraft: 1.5.10 (latest version)

Additional context
Note: I included Electroblob's Wizardry and Ancient Spellcraft, so that more Global Markers would be created.. but the issues exist without these mods as well.

Alternatively, solutions for the above issues would be to have the Antique Atlas automatically do the following:

1. The first time a Server is started with the Antique Atlas mod installed, check any Chunks already generated for any structures that would have created Global Markers (such as villages, nether portals, wizard towers, battlemage camps, sage hills, etc) and generate a Global Marker in aAtlasGlobalMarkers.dat for them. (Issue 1)
2. Each time the Server is started after the Antique Atlas mod has been installed, check for any deleted Chunks and delete any Global Markers found in those chunks. Issue 2
3. When advanced tooltips is turned on, make the Global Markers show a ID when hovering over them in the in-game Atlas GUI so they can be looked up in and edited in the aAtlasGlobalMarkers.dat file. Issue 3