Revert "[GH-5915] Clicking on @mention of a user in a post shows the profile popover (#6129)" (#6289)

This reverts commit 83f819451a.

webapp/tests/utils/formatting_at_mentions.test.jsx

@@ -50,6 +50,21 @@ describe('TextFormatting.AtMentions', function() {
         );
     });
 
+    it('Implied at mentions', function() {
+        // PLT-4454 Assume users exist for things that look like at mentions until we support the new mention syntax
+        assert.equal(
+            TextFormatting.autolinkAtMentions('@user', new Map(), {}),
+            '$MM_ATMENTION0',
+            'should imply user exists and replace mention with token'
+        );
+
+        assert.equal(
+            TextFormatting.autolinkAtMentions('@user.', new Map(), {}),
+            '$MM_ATMENTION0.',
+            'should assume username doesn\'t end in punctuation'
+        );
+    });
+
     it('Not at mentions', function() {
         assert.equal(
             TextFormatting.autolinkAtMentions('user@host', new Map(), {user: {}, host: {}}),
@@ -60,28 +75,5 @@ describe('TextFormatting.AtMentions', function() {
             TextFormatting.autolinkAtMentions('user@email.com', new Map(), {user: {}, email: {}}),
             'user@email.com'
         );
-
-        assert.equal(
-            TextFormatting.autolinkAtMentions('@user', new Map(), {}),
-            '@user'
-        );
-
-        assert.equal(
-            TextFormatting.autolinkAtMentions('@user.', new Map(), {}),
-            '@user.',
-            'should assume username doesn\'t end in punctuation'
-        );
-
-        assert.equal(
-            TextFormatting.autolinkAtMentions('@will', new Map(), {william: {}}),
-            '@will',
-            'should return same text without token'
-        );
-
-        assert.equal(
-            TextFormatting.autolinkAtMentions('@william', new Map(), {will: {}}),
-            '@william',
-            'should return same text without token'
-        );
     });
 });

webapp/tests/utils/formatting_hashtags.test.jsx

@@ -166,7 +166,7 @@ describe('TextFormatting.Hashtags', function() {
         };
         assert.equal(
             TextFormatting.formatText('#@test', options).trim(),
-            "<p>#<span data-mention='test'><a class='mention-link' href='#'>@test</a></span></p>"
+            "<p>#<a class='mention-link' href='#' data-mention='test'>@test</a></p>"
         );
 
         assert.equal(