feat(iOS): rewrite DRM Module (#4136)

* minimal api

* add suport for `getLicense`

* update logic for obtaining `assetId`

* add support for localSourceEncryptionKeyScheme

* fix typo

* fix pendingLicenses key bug

* lint code

* code clean

* code clean

* remove old files

* fix tvOS build

* fix errors loop

* move `localSourceEncryptionKeyScheme` into drm params

* add check for drm type

* use DebugLog

* lint

* update docs

* lint code

* fix bad rebase

* update docs

* fix crashes on simulators

* show error on simulator when using DRM

* fix typos

* code clean

ios/Video/DataStructures/VideoSource.swift

@@ -10,7 +10,7 @@ struct VideoSource {
     let cropEnd: Int64?
     let customMetadata: CustomMetadata?
     /* DRM */
-    let drm: DRMParams?
+    let drm: DRMParams
     var textTracks: [TextTrack] = []
 
     let json: NSDictionary?
@@ -28,7 +28,7 @@ struct VideoSource {
             self.cropStart = nil
             self.cropEnd = nil
             self.customMetadata = nil
-            self.drm = nil
+            self.drm = DRMParams(nil)
             return
         }
         self.json = json