Add icons for AC preset/fan modes not covered by HA's built-ins (#169)

HA's core climate component already ships default icons for common
preset_mode/fan_mode values (eco, away, sleep, auto, low/medium/high,
...), but this integration's own values -- WindFree (nano/nanosleep),
Quiet, Smart, Speed, Long wind, the motion-aware direct/indirect
presets, Dry comfort, 2-Step, and the turbo/max fan speeds some boards
report -- fall outside that vocabulary and rendered with the generic
circle-dot fallback (the icon the #169 screenshot is missing). Adds
icons.json with an icon per value, mirroring the state-label catalog
these same values already have in translations/en.json.

custom_components/localthings/icons.json

@@ -0,0 +1,31 @@
+{
+  "entity": {
+    "climate": {
+      "airconditioner": {
+        "state_attributes": {
+          "fan_mode": {
+            "state": {
+              "turbo": "mdi:speedometer",
+              "max": "mdi:speedometer"
+            }
+          },
+          "preset_mode": {
+            "state": {
+              "ai_comfort": "mdi:creation",
+              "quiet": "mdi:volume-off",
+              "smart": "mdi:brain",
+              "speed": "mdi:speedometer",
+              "nano": "mdi:weather-windy-variant",
+              "nanosleep": "mdi:sleep",
+              "longwind": "mdi:weather-windy",
+              "motiondirect": "mdi:account-arrow-right",
+              "motionindirect": "mdi:account-arrow-left",
+              "drycomfort": "mdi:water-percent",
+              "2step": "mdi:stairs"
+            }
+          }
+        }
+      }
+    }
+  }
+}