impl: model for the IDE product

This is the IDE model from the https://data.services.jetbrains.com/products? feed.
Only `release` and `eap` IDEs will be supported for now.

This commit is in preparation for supporting placeholders like `last_release` or `last_eap`
in the URI handler. Unfortunately Toolbox does not expose a way to determine if a build like
251.2829.367 is an eap build or an actual release, so we have to look up the metadata in the
feed mentioned earlier.

Author: fioan89

src/main/kotlin/com/coder/toolbox/feed/FeedModels.kt

@@ -0,0 +1,87 @@
+package com.coder.toolbox.feed
+
+import com.squareup.moshi.FromJson
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+import com.squareup.moshi.ToJson
+
+/**
+ * Represents a JetBrains IDE product from the feed API.
+ *
+ * The API returns an array of products, each with a code and a list of releases.
+ */
+@JsonClass(generateAdapter = true)
+data class IdeProduct(
+    @Json(name = "code") val code: String,
+    @Json(name = "intellijProductCode") val intellijProductCode: String,
+    @Json(name = "name") val name: String,
+    @Json(name = "releases") val releases: List<IdeRelease> = emptyList()
+)
+
+/**
+ * Represents an individual release of a JetBrains IDE product.
+ */
+@JsonClass(generateAdapter = true)
+data class IdeRelease(
+    @Json(name = "build") val build: String,
+    @Json(name = "version") val version: String,
+    @Json(name = "type") val type: IdeType,
+    @Json(name = "date") val date: String
+)
+
+/**
+ * Type of IDE release: release or EAP (Early Access Program)
+ */
+enum class IdeType {
+    RELEASE,
+    EAP,
+    UNSUPPORTED;
+
+    val value: String
+        get() = when (this) {
+            RELEASE -> "release"
+            EAP -> "eap"
+            UNSUPPORTED -> "unsupported"
+        }
+}
+
+class IdeTypeAdapter {
+    @FromJson
+    fun fromJson(type: String): IdeType {
+        return when (type.lowercase()) {
+            "release" -> IdeType.RELEASE
+            "eap" -> IdeType.EAP
+            else -> IdeType.UNSUPPORTED
+        }
+    }
+
+    @ToJson
+    fun toJson(type: IdeType): String = type.value
+}
+
+/**
+ * Simplified representation of an IDE for use in the plugin.
+ *
+ * Contains the essential information: product code, build number, version, and type.
+ */
+@JsonClass(generateAdapter = true)
+data class Ide(
+    val code: String,
+    val build: String,
+    val version: String,
+    val type: IdeType
+) {
+    companion object {
+        /**
+         * Create an Ide from an IdeProduct and IdeRelease.
+         */
+        fun from(product: IdeProduct, release: IdeRelease): Ide {
+            return Ide(
+                code = product.intellijProductCode,
+                build = release.build,
+                version = release.version,
+                type = release.type
+            )
+        }
+    }
+}