[MM-380] Fix issue of todo permalink opening in new tab

[ayusht2810]

Summary

Fixed issue of todo permalink opening in new tab

Demo

screen-capture.3.webm

Ticket Link

Fixes #164

What to test?

• Create a todo from a post
• Check for the permalink created in RHS, which should open in the same tab
• Create and assign a permalink to another user
• The todo's permalink assigned to another user should also open in the same tab
• Similarly, test for other actions like rejecting/accepting/completing a todo

[mickmister]

Great work 👍 Just a few comments

[mickmister]

Seems like this could just accept a issue instead of these 4 fields derived from the issue

[ayusht2810]

@mickmister This function https://github.com/mattermost/mattermost-plugin-todo/blob/b8dff94f7bebfcb7f81f36f588f110e08e34ef9f/server/issue.go#L27 just return a new object with passed parameters value. At some places https://github.com/mattermost/mattermost-plugin-todo/blob/b8dff94f7bebfcb7f81f36f588f110e08e34ef9f/server/list.go#L62 we are passing the value directly instead of the case above

[mickmister]

What happens for posts that do not have this prop?

[ayusht2810]

If we don't have this prop, we won't have a permalink in the message in the todo sent to other user in the post

[AayushChaudhary0001]

This PR was tested and I found an issue in its functionality

Steps to reproduce:-

1. Create any todo through a post in a channel.
2. Once the Todo is reflected in RHS and is ready to be created, click spacebar against the name of the todo, it will create 2 permalinks.
3. Click on the bottom permalink.

The permalink present in the bottom will not redirect you to a new page, instead the user will remain on the same page.

cc: @mickmister

[Kshitij-Katiyar]

@AayushChaudhary0001 I have fixed the issue reported. Please have a look.
CC: @mickmister , @wiggin77

[AayushChaudhary0001]

@raghavaggarwal2308 The above PR has been re-tested and the above issue has been resolved. Approving this PR, LGTM.