[rdct-tests]: make test API agent context aware + Editors API refactoring

Huge thanks to Artem Bukhonov

GitOrigin-RevId: 7382c8773dd5f026e1ad174bb2a1d90d03c49a65

platform/remoteDev-util/src/com/intellij/remoteDev/tests/AgentContext.kt

@@ -9,13 +9,37 @@ import org.jetbrains.annotations.ApiStatus
 /**
  * Provides access to all essential entities on this agent required to perform test operations
  */
-@ApiStatus.Internal
-class AgentContext(
-  val agentId: RdAgentId,
-  val application: Application,
-  val projectOrNull: Project?,
+interface AgentContext {
+  val agentId: RdAgentId
+  val application: Application
+  val projectOrNull: Project?
   val protocol: IProtocol
-) {
   val project: Project
     get() = projectOrNull ?: error("Project shouldn't be requested for the projectless application")
+  companion object {
+    fun create(agentId: RdAgentId,
+               application: Application,
+               projectOrNull: Project?,
+               protocol: IProtocol) : AgentContext {
+      return AgentContextImpl(agentId, application, projectOrNull, protocol)
+    }
+  }
 }
+
+@ApiStatus.Internal
+interface HostContext : AgentContext
+@ApiStatus.Internal
+interface GatewayContext : AgentContext
+@ApiStatus.Internal
+interface ClientContext : AgentContext
+
+// If you need some extra data or behavior for a particular class, e.g. HostContext should have some host specific data, just derive from
+// the AgentContextImpl and derive it also from HostContext
+// then create proper inheritor in AgentContext.create() depending on agentId
+@ApiStatus.Internal
+internal class AgentContextImpl(
+  override val agentId: RdAgentId,
+  override val application: Application,
+  override val projectOrNull: Project?,
+  override val protocol: IProtocol
+) : HostContext, ClientContext, GatewayContext

platform/remoteDev-util/src/com/intellij/remoteDev/tests/impl/DistributedTestHost.kt

@@ -127,7 +127,7 @@ class DistributedTestHost {
 
               // Execute test method
               lateinit var result: RdTask<Boolean>
-              val context = AgentContext(session.agentId, application, projectOrNull, protocol)
+              val context = AgentContext.create(session.agentId, application, projectOrNull, protocol)
               logger.info("'$actionTitle': starting action")
               val elapsedAction = measureTimeMillis {
                 result = action.action.invoke(context)