feat(content): `add residential lawn nested chunk variants'

[LilShiningMan]

Purpose of change

Fleshing out residential lawn nested chunk spawn variety, in order to make house spawns more dynamic and try to add a little life and dimension.

Describe the solution

Add variant nested chunks that can spawn in backyards, frontyards or both. Also, adding other nested chunks to spawn list that already exist in the game (a few of my roof nested chunks and 3X3 garden plots). Some of these chunks are decorative (gardens), some have tools or vehicles (kayaks, bikes, shovels, etc.), others just have incidental little bits or ambient storytelling (animal spawns, abandoned suitcase, etc.).

Also added a snippets file for the yard sign spawn.

Describe alternatives you've considered

Testing

Linted and spawned in game. Screenshots below.

Additional context

Currently the front and backyard nested chunks only spawn in house_fence09, bungalow27 and bungalow28. I aim to add these to all of the houses I've created (where possible), but before I do that I want to actually add some content to make this worthwhile.

My previous PRs (#4281 and #4282) added 2 variants apiece for front and back. This PR has some chunks that can spawn in both, along with some unique to either front or back.

wheelbarrow and shovel

kayaks, tarped up for storage (tarps unfortunately only show when kayaks dragged away)

yard sign

random trash

cats hunting a rat

kids' slide in backyard

bike

electric scooter, tarped up

garden with log marker

backyard firepit

lawndarts

lawnmower

flowerpots

table and chairs

spilled suitcase

Checklist

• I wrote the PR title in conventional commit format, see above
• I ran the code formatter
• I linked any relevant issues using github keyword syntax