Delete Text V2 plugin code. (#6258)

The Text V2 plugin was an intern project attempting to build a new
"Text" plugin in Angular. It was never completed. We now delete it.

Author: bmd3k

tensorboard/BUILD

@@ -321,7 +321,6 @@ py_library(
         "//tensorboard/plugins/profile_redirect:profile_redirect_plugin",
         "//tensorboard/plugins/scalar:scalars_plugin",
         "//tensorboard/plugins/text:text_plugin",
-        "//tensorboard/plugins/text_v2:text_v2_plugin",
     ],
 )
 

tensorboard/default.py

@@ -44,22 +44,13 @@
 from tensorboard.plugins.profile_redirect import profile_redirect_plugin
 from tensorboard.plugins.scalar import scalars_plugin
 from tensorboard.plugins.text import text_plugin
-from tensorboard.plugins.text_v2 import text_v2_plugin
 from tensorboard.plugins.mesh import mesh_plugin
 from tensorboard.plugins.npmi import npmi_plugin
 
 
 logger = logging.getLogger(__name__)
 
 
-class ExperimentalTextV2Plugin(
-    text_v2_plugin.TextV2Plugin, experimental_plugin.ExperimentalPlugin
-):
-    """Angular Text Plugin marked as experimental."""
-
-    pass
-
-
 class ExperimentalNpmiPlugin(
     npmi_plugin.NpmiPlugin, experimental_plugin.ExperimentalPlugin
 ):
@@ -86,7 +77,6 @@ class ExperimentalNpmiPlugin(
     profile_redirect_plugin.ProfileRedirectPluginLoader,
     hparams_plugin.HParamsPlugin,
     mesh_plugin.MeshPlugin,
-    ExperimentalTextV2Plugin,
     ExperimentalNpmiPlugin,
 ]