refactor(ContentType.java): add the ContentType class back. Full implementation is still missing

mastodon/src/main/java/org/joinmastodon/android/model/ContentType.java

@@ -0,0 +1,39 @@
+package org.joinmastodon.android.model;
+
+import android.view.Menu;
+
+import androidx.annotation.Nullable;
+
+import com.google.gson.annotations.SerializedName;
+
+import org.joinmastodon.android.R;
+
+public enum ContentType {
+	@SerializedName("text/plain")
+	PLAIN,
+	@SerializedName("text/html")
+	HTML,
+	@SerializedName("text/markdown")
+	MARKDOWN,
+	@SerializedName("text/bbcode")
+	BBCODE, // akkoma
+	@SerializedName("text/x.misskeymarkdown")
+	MISSKEY_MARKDOWN, // akkoma/*key
+	@SerializedName("")
+	UNSPECIFIED;
+
+	public int getName() {
+		return switch(this) {
+			case PLAIN -> R.string.sk_content_type_plain;
+			case HTML -> R.string.sk_content_type_html;
+			case MARKDOWN -> R.string.sk_content_type_markdown;
+			case BBCODE -> R.string.sk_content_type_bbcode;
+			case MISSKEY_MARKDOWN -> R.string.sk_content_type_mfm;
+			case UNSPECIFIED -> R.string.sk_content_type_unspecified;
+		};
+	}
+
+	public boolean supportedByInstance(Instance i) {
+		return i.isAkkoma() || (this!=BBCODE && this!=MISSKEY_MARKDOWN);
+	}
+}