PLT-7379: Timestamp on deleted, ephemeral, or pending post is a permalink (#7295)

* Removed permalink from system messages, general cleanup

* Removed permalink from deleted messages

* Removed permalink from pending messages

* Fixed post_info tests

* Changed permalink logic to remove permalinks from ephemeral messages, but leave them in place for system messages.

* Fixed check style

webapp/tests/components/post_view/post_info/__snapshots__/post_info.test.jsx.snap

@@ -9,6 +9,7 @@ exports[`components/post_view/PostInfo should match snapshot 1`] = `
   >
     <PostTime
       eventTime={1502715365009}
+      isPermalink={true}
       postId="e584uzbwwpny9kengqayx5ayzw"
       useMilitaryTime={false}
     />
@@ -98,6 +99,7 @@ exports[`components/post_view/PostInfo should match snapshot, compact display 1`
   >
     <PostTime
       eventTime={1502715365009}
+      isPermalink={true}
       postId="e584uzbwwpny9kengqayx5ayzw"
       useMilitaryTime={false}
     />
@@ -187,6 +189,7 @@ exports[`components/post_view/PostInfo should match snapshot, ephemeral deleted
   >
     <PostTime
       eventTime={1502715365009}
+      isPermalink={false}
       postId="e584uzbwwpny9kengqayx5ayzw"
       useMilitaryTime={false}
     />
@@ -222,6 +225,7 @@ exports[`components/post_view/PostInfo should match snapshot, ephemeral post 1`]
   >
     <PostTime
       eventTime={1502715365009}
+      isPermalink={false}
       postId="e584uzbwwpny9kengqayx5ayzw"
       useMilitaryTime={false}
     />
@@ -266,6 +270,7 @@ exports[`components/post_view/PostInfo should match snapshot, flagged post 1`] =
   >
     <PostTime
       eventTime={1502715365009}
+      isPermalink={true}
       postId="e584uzbwwpny9kengqayx5ayzw"
       useMilitaryTime={false}
     />
@@ -355,6 +360,7 @@ exports[`components/post_view/PostInfo should match snapshot, military time 1`]
   >
     <PostTime
       eventTime={1502715365009}
+      isPermalink={true}
       postId="e584uzbwwpny9kengqayx5ayzw"
       useMilitaryTime={true}
     />
@@ -418,6 +424,7 @@ exports[`components/post_view/PostInfo should match snapshot, pinned post 1`] =
   >
     <PostTime
       eventTime={1502715365009}
+      isPermalink={true}
       postId="e584uzbwwpny9kengqayx5ayzw"
       useMilitaryTime={false}
     />