Move ICE code out of internal

Users are unable to use the callbacks inside `internal/ice`.
Even though we alias things like OnSelectedCandidatePairChange
are unusable since in the package they use `ice.Candidate` instead of
`ICECandidate`

Author: Sean-Der

.travis.yml

@@ -39,10 +39,8 @@ script:
   - cd examples && golangci-lint run --build-tags quic ./... -D gochecknoinits
   - cd ..
   - rm -rf examples # Remove examples, no test coverage for them
-  - rm -rf internal/tools # Remove tools, no test coverage for them
   - go test -tags quic -coverpkg=$(go list ./... | tr '\n' ',') -coverprofile=cover.out -v -race -covermode=atomic ./...
-  - GOOS=js GOARCH=wasm go test -exec="${PWD}/test-wasm/go_js_wasm_exec" -v .
-  - GOOS=js GOARCH=wasm go test -exec="${PWD}/test-wasm/go_js_wasm_exec" -v ./internal/ice
+  - GOOS=js GOARCH=wasm go test -exec="./test-wasm/go_js_wasm_exec" -v .
   - bash <(curl -s https://codecov.io/bash)
   - bash .github/assert-contributors.sh
   - bash .github/lint-disallowed-functions-in-library.sh

errors.go

@@ -19,6 +19,14 @@ var (
 	// ErrCertificateExpired indicates that an x509 certificate has expired.
 	ErrCertificateExpired = errors.New("x509Cert expired")
 
+	// ErrNoTurnCredencials indicates that a TURN server URL was provided
+	// without required credentials.
+	ErrNoTurnCredencials = errors.New("turn server credentials required")
+
+	// ErrTurnCredencials indicates that provided TURN credentials are partial
+	// or malformed.
+	ErrTurnCredencials = errors.New("invalid turn server credentials")
+
 	// ErrExistingTrack indicates that a track already exists.
 	ErrExistingTrack = errors.New("track already exists")
 

ice.go

@@ -2,35 +2,7 @@
 
 package webrtc
 
-import (
-	"github.com/pion/sdp/v2"
-
-	"github.com/pion/webrtc/v2/internal/ice"
-)
-
-//go:generate go run internal/tools/gen/genaliasdocs.go -pkg "./internal/ice" -build-tags "!js" $GOFILE
-
-type (
-
-	// ICETransport allows an application access to information about the ICE
-	// transport over which packets are sent and received.
-	ICETransport = ice.Transport
-
-	// ICEGatherer gathers local host, server reflexive and relay
-	// candidates, as well as enabling the retrieval of local Interactive
-	// Connectivity Establishment (ICE) parameters which can be
-	// exchanged in signaling.
-	ICEGatherer = ice.Gatherer
-)
-
-var (
-
-	// NewICEGatherer creates a new NewICEGatherer.
-	NewICEGatherer = ice.NewGatherer
-
-	// NewICETransport creates a new NewICETransport.
-	NewICETransport = ice.NewTransport
-)
+import "github.com/pion/sdp/v2"
 
 // NewICEGatherer creates a new NewICEGatherer.
 // This constructor is part of the ORTC API. It is not