Add AppearsOnMapPreview

[MustaphaTR]

Adds required logic to fix "#12097 and #13823". Tho i haven't actually updated any map to actually fix the issue.

I put a testcase for stuff that preferably be rendered on RA mod. You can test by opening a map and saving it (seems like it requires a restart so it'll show the new preview).

[SoScared]

I assume you want to put RenderOnMapPreview on ^Building as well https://github.com/OpenRA/OpenRA/pull/15731/files#diff-5b0780203fcfc47fcb88e0b8d6d306b9R638

[pchote]

This is a high impact feature, so adding it to the milestone.

Updated.

[pchote]

I have pushed over this with some changes to streamline the feature plumbing. 👍 to that part of the PR now.

Two things left to go:

• Add AppearsOnMapPreview to the other default mods.
• Implement an update rule and update all the default maps - we will need to add new plumbing to the update rule infrastructure, so might be best if I handle this part.

[pchote]

Ping @MustaphaTR

[pchote]

I would have really liked this for the current release, but the amount of work here (including regenerating all maps and getting them on the resource center) is too risky for the short window that remains for prepping a christmas playtest. Bumping to Next + 1.

[MustaphaTR]

Implement an update rule and update all the default maps - we will need to add new plumbing to the update rule infrastructure, so might be best if I handle this part.

I think last we agreed that you were going to do this and i would do the updating the shipped maps.

[pchote]

I've been waiting for the other mods to be updated, which is checked in the list above but not actually done!?

[MustaphaTR]

Ok, i thought i've done that, but it appears that i have actually only appied it to RA. Will rebase this first and do so.

[MustaphaTR]

Updated.

[MustaphaTR]

Updated.

[pchote]

I'll file a followup PR that makes some tweaks to the map.yaml formatting, adds a new --refresh-map utility command, and ports over the default mod maps after this has been merged.

[pchote]

Confirmed that AppearsOnMapPreview is now declared on all actors that use RadarColorFromTerrain plus tech structures and walls. The rest of the code still LGTM.

[reaperrr]

https://github.com/OpenRA/OpenRA/wiki/Changelog-(bleed)/_compare/b926bc9da4879f30faf68fddaeb00eae07f7aa69...780e3855e6b89beb439b3100c5ed136d71e0b86c