Add tags to issue with context menu

[yzzy]

PR for #158

[marius-balteanu]

Interesting feature.

I'll take a look this week or in weekend. @yzzy, do you in plan to add some tests for this feature?

[yzzy]

@marius-balteanu, I'm used to programming without writing tests and this approach is very new to me. I'm trying to understand this technique right now, but I think I'll write tests for front-end behavior not yet soon. Sorry.

[marius-balteanu]

I quickly tested now your PR and I found multiple issue that should be addressed before accepting this.

1. Context menu with tags doesn't work for multiple issues

• Select at least 2 issue from the issues list
• Open the context menu
• Observe that the "Tags" option is missing
  

2. Current tags are listed in the context menu, but the functionality is not clear.
   
   When I click an existing tag, I'm redirected to issues list filtered by the respective tag. This is the expected behaviour?

3. Same for the tags listed in the modal. We should remove the link and make the tag name a label for the checkbox (in that way, when you click the tag name, the checkbox will be checked).

[yzzy]

First, I'd like to say thank you for testing my code. I apologize for missing unit tests looking at which you'll stand on my point of view of this new functionality.
Here are my answers:

1. This behavior is by design. I intentionally didn't mix this approach of tags editing with bulk-edit operations.

2. I assumed that issue's tags enumeration on drop-down list gives additional information before the redminer decides whether to click the "add" button. If you think it's redundancy I'll remove this list. Redirecting to issues list filtered by tag after clicking its name is a defect for sure. If you decide to keep tags list in drop-down state I'll turn it to text strings.

3. You're right, it will be much better. I'll work it out.

Please clarify if I should request a new PR after code modification.

[lcasanova78]

Finally what happened with this request, I just installed it and in the context menu there is no tag option either with a single issue or in bulk.