Add investment user tags admin interface

[ortegacmanuel]

Where

• Related Issue: Add investment's user generated tags to admin interface #1946

What

• Adds investment's user generated tags to admin interface

How

• Following the implementation done in Madrid's fork

Why

There are two kind of tags related to budget investments:

• User tags
• Valuation tags

User tags are the ones added by users when they create an investment.

Valuation tags, are used to internally tag investments.

Case example:

• The Health area of the Government, deals with internal tags for “hospitals and ambulances”
• The Culture area of the Government, deals with internal tags for “theatres and street music”

[bertocq]

Thanks @ortegacmanuel for the backport! :) I would have cherrypicked the commit from madrid's fork btw (adding the repo as a remote)

[ortegacmanuel]

@bertocq My pleasure :) Thanks for the comment about cherrypicking the commit from madrid's fork...I'll keep this in mind for next one ;)