FIX: BBCode tag parser

Wasn't quite handling the cases where a closing bracket `]` was used in the value of one of the attributes.

```markdown
[chat quote=user channel="[broken]"]
```

Would not be correctly parsed because we would _greedily_ use the first `]` as the end of the tag even though it might be a valid character when inside proper quotes.

c39a4de139/app/assets/javascripts/discourse-markdown-it/src/features/bbcode-block.js (L62)

Re-wrote the `parseBBCodeTag` to properly handle the following cases

- A closing tag (aka `[/name]`) which are easy since they don't have any attributes
- An old `[quote=...]` format we used that doesn't uses quotes but still has various attributes of the form `key:value`
- All three valid BBCode opening tag formats we support
  - `[name]` without any attributes
  - `[name=foo]` with a default value
  - `[name foo=bar]` with some attributes

Ended up having to fix/rewrite the few bbcode rules that were using the `parseBBCodeTag` function, namely `d-wrap` and `discourse-local-dates`.

While working on this, I think I also found a way to get rid the of shims we had in place so that plugins could use the `parseBBCodeTag` function.

Reference - https://meta.discourse.org/t/having-a-right-bracket-in-a-channel-name-breaks-all-quotes-from-that-channel/308439

plugins/discourse-local-dates/spec/lib/pretty_text_spec.rb

@@ -2,13 +2,13 @@
 
 def generate_html(text, opts = {})
   output = "<p><span"
-  output += " data-date=\"#{opts[:date]}\"" if opts[:date]
-  output += " data-time=\"#{opts[:time]}\"" if opts[:time]
   output += " class=\"discourse-local-date\""
-  output += " data-timezones=\"#{opts[:timezones]}\"" if opts[:timezones]
-  output += " data-timezone=\"#{opts[:timezone]}\"" if opts[:timezone]
-  output += " data-format=\"#{opts[:format]}\"" if opts[:format]
+  output += " data-date=\"#{opts[:date]}\"" if opts[:date]
   output += " data-email-preview=\"#{opts[:email_preview]}\"" if opts[:email_preview]
+  output += " data-format=\"#{opts[:format]}\"" if opts[:format]
+  output += " data-time=\"#{opts[:time]}\"" if opts[:time]
+  output += " data-timezone=\"#{opts[:timezone]}\"" if opts[:timezone]
+  output += " data-timezones=\"#{opts[:timezones]}\"" if opts[:timezones]
   output += ">"
   output += text
   output + "</span></p>"