feat: Add pricing models to represent the various pricing objects from the API response (#52)

Author: BigDaddyJay90

src/main/kotlin/net/tcgdex/sdk/models/Card.kt

@@ -62,6 +62,10 @@ data class Card internal constructor(
 	 */
 	val set: SetResume,
 
+    /**
+     * 	Market pricing information
+     */
+    val pricing: Pricing?,
 
 	/**
 	 * the Pokémon Pokédex IDs (multiple if multiple pokémon appears on the card)

src/main/kotlin/net/tcgdex/sdk/models/Pricing.kt

@@ -0,0 +1,13 @@
+package net.tcgdex.sdk.models
+
+import net.tcgdex.sdk.internal.Model
+import net.tcgdex.sdk.models.subs.PricingCardMarket
+import net.tcgdex.sdk.models.subs.PricingTcgPlayer
+
+/**
+ * Pokémon TCG Pricing class
+ */
+data class Pricing internal constructor(
+    val tcgplayer: PricingTcgPlayer?,
+    val cardmarket: PricingCardMarket?
+) : Model()

src/main/kotlin/net/tcgdex/sdk/models/subs/PricingCardMarket.kt

@@ -0,0 +1,85 @@
+package net.tcgdex.sdk.models.subs
+
+import com.google.gson.annotations.SerializedName
+import net.tcgdex.sdk.internal.Model
+
+/**
+ * Pokémon TCG PricingCardMarket class
+ */
+data class PricingCardMarket internal constructor(
+    /**
+     * Indicate when is the last time it was fetched
+     */
+    val updated: String?,
+
+    /**
+     * Indicate the unit in which the card is sold
+     */
+    val unit: String?,
+
+    /**
+     * Average selling price (non-foil)
+     */
+    val avg: Float?,
+
+    /**
+     * Lowest market price (non-foil)
+     */
+    val low: Float?,
+
+    /**
+     * Trend price from charts (non-foil)
+     */
+    val trend: Float?,
+
+    /**
+     * Average price (last 24 hours)
+     */
+    val avg1: Float?,
+
+    /**
+     * 	Average price (last 7 days)
+     */
+    val avg7: Float?,
+
+    /**
+     * Average price (last 30 days)
+     */
+    val avg30: Float?,
+
+    /**
+     * Average selling price (foil)
+     */
+    @SerializedName("avg-holo")
+    val avgHolo: Float?,
+
+    /**
+     * Lowest market price (foil)
+     */
+    @SerializedName("low-holo")
+    val lowHolo: Float?,
+
+    /**
+     * Trend price from charts (foil)
+     */
+    @SerializedName("trend-holo")
+    val trendHolo: Float?,
+
+    /**
+     * Average price (last 24 hours, foil)
+     */
+    @SerializedName("avg1-holo")
+    val avg1Holo: Float?,
+
+    /**
+     * Average price (last 7 days, foil)
+     */
+    @SerializedName("avg7-holo")
+    val avg7Holo: Float?,
+
+    /**
+     * Average price (last 30 days, foil)
+     */
+    @SerializedName("avg30-holo")
+    val avg30Holo: Float?
+) : Model()

src/main/kotlin/net/tcgdex/sdk/models/subs/PricingTcgPlayer.kt

@@ -0,0 +1,58 @@
+package net.tcgdex.sdk.models.subs
+
+import com.google.gson.annotations.SerializedName
+import net.tcgdex.sdk.internal.Model
+
+/**
+ * Pokémon TCG PricingTcgPlayer class
+ */
+data class PricingTcgPlayer internal constructor(
+    /**
+     * Indicate when is the last time it was fetched
+     */
+    val updated: String,
+
+    /**
+     * Indicate the unit in which the card is sold
+     */
+    val unit: String,
+
+    /**
+     * Standard non-foil cards
+     */
+    val normal: PricingTcgPlayerVariant?,
+
+    /**
+     * Holofoil finish cards
+     */
+    val holoFoil: PricingTcgPlayerVariant?,
+
+    /**
+     * Reverse holofoil cards
+     */
+    @SerializedName("reverse-holofoil")
+    val reverseHolofoil: PricingTcgPlayerVariant?,
+
+    /**
+     * First edition cards
+     */
+    @SerializedName("1st-edition")
+    val firstEdition: PricingTcgPlayerVariant?,
+
+    /**
+     * First edition holofoil cards
+     */
+    @SerializedName("1st-edition-holofoil")
+    val firstEditionHolofoil: PricingTcgPlayerVariant?,
+
+    /**
+     * Unlimited edition cards
+     */
+    val unlimited: PricingTcgPlayerVariant?,
+
+    /**
+     * Unlimited holofoil cards
+     */
+    @SerializedName("unlimited-holofoil")
+    val unlimitedHolofoil: PricingTcgPlayerVariant?
+) : Model()

src/main/kotlin/net/tcgdex/sdk/models/subs/PricingTcgPlayerVariant.kt

@@ -0,0 +1,31 @@
+package net.tcgdex.sdk.models.subs
+
+/**
+ * Pokémon TCG PricingTcgPlayerVariant class
+ */
+data class PricingTcgPlayerVariant internal constructor(
+    /**
+     * Lowest available price
+     */
+    val lowPrice: Float?,
+
+    /**
+     * Median market price
+     */
+    val midPrice: Float?,
+
+    /**
+     * Highest available price
+     */
+    val highPrice: Float?,
+
+    /**
+     * Current market price
+     */
+    val marketPrice: Float?,
+
+    /**
+     * Lowest direct seller price
+     */
+    val directLowPrice: Float?
+)