PLT-5367: Basic post bulk importing. (#5562)

i18n/en.json

@@ -2983,6 +2983,50 @@
     "id": "app.import.validate_user_teams_import_data.team_name_missing.error",
     "translation": "Team name missing from User's Team Membership."
   },
+  {
+    "id": "app.import.import_post.team_not_found.error",
+    "translation": "Error importing post. Team with name \"{{.TeamName}}\" could not be found."
+  },
+  {
+    "id": "app.import.import_post.channel_not_found.error",
+    "translation": "Error importing post. Channel with name \"{{.ChannelName}}\" could not be found."
+  },
+  {
+    "id": "app.import.import_post.user_not_found.error",
+    "translation": "Error importing post. User with username \"{{.Username}}\" could not be found."
+  },
+  {
+    "id": "app.import.validate_post_import_data.team_missing.error",
+    "translation": "Missing required Post property: Team."
+  },
+  {
+    "id": "app.import.validate_post_import_data.channel_missing.error",
+    "translation": "Missing required Post property: Channel."
+  },
+  {
+    "id": "app.import.validate_post_import_data.user_missing.error",
+    "translation": "Missing required Post property: User."
+  },
+  {
+    "id": "app.import.validate_post_import_data.message_missing.error",
+    "translation": "Missing required Post property: Message."
+  },
+  {
+    "id": "app.import.validate_post_import_data.create_at_missing.error",
+    "translation": "Missing required Post property: create_at."
+  },
+  {
+    "id": "app.import.validate_post_import_data.message_length.error",
+    "translation": "Post Message property is longer than the maximum permitted length."
+  },
+  {
+    "id": "app.import.validate_post_import_data.create_at_zero.error",
+    "translation": "Post CreateAt must not be zero if it is provided."
+  },
+  {
+    "id": "app.import.import_line.null_post.error",
+    "translation": "Import data line has type \"post\" but the post object is null."
+  },
   {
     "id": "authentication.permissions.create_team_roles.description",
     "translation": "Ability to create new teams"
@@ -4943,6 +4987,10 @@
     "id": "store.sql_post.get_posts_around.get.app_error",
     "translation": "We couldn't get the posts for the channel"
   },
+  {
+    "id": "store.sql_post.get_posts_created_att.app_error",
+    "translation": "We couldn't get the posts for the channel"
+  },
   {
     "id": "store.sql_post.get_posts_around.get_parent.app_error",
     "translation": "We couldn't get the parent posts for the channel"
@@ -4991,6 +5039,10 @@
     "id": "store.sql_post.update.app_error",
     "translation": "We couldn't update the Post"
   },
+  {
+    "id": "store.sql_post.overwrite.app_error",
+    "translation": "We couldn't overwrite the Post"
+  },
   {
     "id": "store.sql_preference.delete.app_error",
     "translation": "We encountered an error while deleting preferences"