Various bugs with Tagging of Cases and Activities

Found the following issues using Tags with Cases and Activities (screenshots attached):

1. Manage Case (CaseView.php): Case Tags pane
If I've assigned one or more tags to the case, when I click "Change Tags" the dialog doesn't load in the tags already assigned to this case. This means I have to reselect them or they will be removed. NOTE: This widget sets defaults / works properly when used in Activity form.

2. Manage Case: Case Tags pane AND Open Case form
Although I can set a Tagset as Used For = Case, there's currently no way to actually tag a case. To recreate - add a Tagset, Used For = Case. The input form is not shown in Case Tags pane, Add/Change Tags dialog, nor in Open Case form.

3. Tag an Activity with a Tagset tag
3.1 If my Tagset has Used For = Activities, I get the input field in the Activity Form. However the code which assigns tags to activities (i.e. creates entity_tag records) is quite buggy. When I type in a keyword value and save it, I got that "tag" assigned TWICE (two identical rows in entity_tag). If I then select another keyword (new or existing tag - doesn't seem to matter) - now I have 4 instances of the new one. etc ....

3.2. Activity view includes the Tagset INPUT field rather than just a list of assigned tags next to the tagset label. We shouldn't be including an editable field here.

3.2 If you save an activity without filling in a tagset tag, you get an error (in the comments)

4. In advanced search, the autcomplete js for tagsets will allow you to enter non-existent tags, and searching on non-existent tags results in a sql error (We should remove the option and fix the sql error just in case) sql error in comment below

5. In advanced search and contact edit form, hierarchy is not displayed for "normal" hierarchical tags (need it in the dropdown select list and in the checkbox list)

6. In the contact edit form tagsets are not displayed in the "Tags and Groups" panel