implement content caching

cache/content/common/build.gradle

@@ -0,0 +1,18 @@
+plugins {
+    id "org.jetbrains.kotlin.multiplatform"
+    id "org.jetbrains.kotlin.plugin.serialization"
+    id "com.android.library"
+}
+
+apply from: "$mppProjectWithSerializationPresetPath"
+
+kotlin {
+    sourceSets {
+        commonMain {
+            dependencies {
+                api "dev.inmo:tgbotapi.core:$tgbotapi_version"
+            }
+        }
+    }
+}
+