feat: implement workspace configuration version pinning (DMD-1086)

Add optional configurationVersion parameter to workspace creation that pins
the workspace to a specific configuration version for deterministic
direct-grant output mapping during unload and drop.

- DB migration adding configurationVersion column to bi_workspaces
- Request validation, processor logic for sync/async paths
- Version-aware unload and drop with proper error handling
- Domain exceptions for deleted versions/tables/configurations
- Response layer with OpenAPI schema updates
- Unit tests (CreateWorkspaceProcessor, WorkspaceUnloadProcessor,
  CreateWorkspaceRequest, ConfigurationParser, WorkspaceResponseProvider)
- E2E tests covering all 8 RFC scenarios

Author: vojtabiberle

src/Keboola/StorageApi/Workspaces.php

@@ -12,6 +12,7 @@
  *      name: string|null,
  *      component: string|null,
  *      configurationId: string|null,
+ *      configurationVersion: int|null,
  *      created: string,
  *      connection: array{
  *       backend: string,
@@ -40,6 +41,7 @@
  * @phpstan-type CreateWorkspaceOptions array{
  *      backend?: string,
  *      backendSize?: string,
+ *      configurationVersion?: int,
  *      loginType?: WorkspaceLoginType,
  *      networkPolicy?: string,
  *      readOnlyStorageAccess?: bool,