trace2: add regions to OAuth

Add region tracing to key methods in OAuth2Client. This was deemed a good
starting point for regions due to the server interaction required to
obtain auth codes, device codes, and tokens. Additional regions can and
should be added to additional sections of the code that are deemed
performance-critical in the future.

Author: ldennington

src/shared/Core/Authentication/OAuth/OAuth2Client.cs

@@ -104,6 +104,9 @@ public IOAuth2CodeGenerator CodeGenerator
         public async Task<OAuth2AuthorizationCodeResult> GetAuthorizationCodeAsync(IEnumerable<string> scopes,
             IOAuth2WebBrowser browser, IDictionary<string, string> extraQueryParams, CancellationToken ct)
         {
+            var label = "get auth code";
+            using IDisposable region = _trace2.CreateRegion(OAuth2Constants.Trace2Category, label);
+
             string state = CodeGenerator.CreateNonce();
             string codeVerifier = CodeGenerator.CreatePkceCodeVerifier();
             string codeChallenge = CodeGenerator.CreatePkceCodeChallenge(OAuth2PkceChallengeMethod.Sha256, codeVerifier);
@@ -183,6 +186,9 @@ public async Task<OAuth2AuthorizationCodeResult> GetAuthorizationCodeAsync(IEnum
 
         public async Task<OAuth2DeviceCodeResult> GetDeviceCodeAsync(IEnumerable<string> scopes, CancellationToken ct)
         {
+            var label = "get device code";
+            using IDisposable region = _trace2.CreateRegion(OAuth2Constants.Trace2Category, label);
+
             if (_endpoints.DeviceAuthorizationEndpoint is null)
             {
                 throw new Trace2InvalidOperationException(_trace2,
@@ -218,6 +224,9 @@ public async Task<OAuth2DeviceCodeResult> GetDeviceCodeAsync(IEnumerable<string>
 
         public async Task<OAuth2TokenResult> GetTokenByAuthorizationCodeAsync(OAuth2AuthorizationCodeResult authorizationCodeResult, CancellationToken ct)
         {
+            var label = "get token by auth code";
+            using IDisposable region = _trace2.CreateRegion(OAuth2Constants.Trace2Category, label);
+
             var formData = new Dictionary<string, string>
             {
                 [OAuth2Constants.TokenEndpoint.GrantTypeParameter] = OAuth2Constants.TokenEndpoint.AuthorizationCodeGrantType,
@@ -254,6 +263,9 @@ public async Task<OAuth2TokenResult> GetTokenByAuthorizationCodeAsync(OAuth2Auth
 
         public async Task<OAuth2TokenResult> GetTokenByRefreshTokenAsync(string refreshToken, CancellationToken ct)
         {
+            var label = "get token by refresh token";
+            using IDisposable region = _trace2.CreateRegion(OAuth2Constants.Trace2Category, label);
+
             var formData = new Dictionary<string, string>
             {
                 [OAuth2Constants.TokenEndpoint.GrantTypeParameter] = OAuth2Constants.TokenEndpoint.RefreshTokenGrantType,
@@ -284,6 +296,9 @@ public async Task<OAuth2TokenResult> GetTokenByRefreshTokenAsync(string refreshT
 
         public async Task<OAuth2TokenResult> GetTokenByDeviceCodeAsync(OAuth2DeviceCodeResult deviceCodeResult, CancellationToken ct)
         {
+            var label = "get token by device code";
+            using IDisposable region = _trace2.CreateRegion(OAuth2Constants.Trace2Category, label);
+
             var formData = new Dictionary<string, string>
             {
                 [OAuth2Constants.DeviceAuthorization.GrantTypeParameter] = OAuth2Constants.DeviceAuthorization.DeviceCodeGrantType,

src/shared/Core/Authentication/OAuth/OAuth2Constants.cs

@@ -7,6 +7,7 @@ public static class OAuth2Constants
         public const string ClientSecretParameter = "client_secret";
         public const string RedirectUriParameter = "redirect_uri";
         public const string ScopeParameter = "scope";
+        public const string Trace2Category = "oauth2";
 
         public static class AuthorizationEndpoint
         {