Implement option to copy a tag

[snake14]

Description:

This PR implements the ability to copy tags. It tries to reuse existing triggers and variables when copying references from the tag. If no matches exist, any dependencies will be copied as well.

Fixes: #615

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed

[AltamashShaikh]

@snake14

1. After copying a tag, there is no notification that its a success or failure.
2. For tags when we click copy the default container should be the current container

I also faced 1 issue of copy tag throwing and error "This name is already in use" when copying a same tag twice in an another container

[AltamashShaikh]

@snake14 The copy notification is getting hidden, if preview mode is enabled

Without preview mode

With preview mode, no notification message is displayed

[snake14]

Thank you for the good review @AltamashShaikh .

It looks like I'm going to have to refactor things so that the notifications are handled via Vue instead of PHP, because the PHP notification just doesn't appear to be reliable enough.

I thought that I had it selecting the current container by default, but I'll make sure.

I have test cases around copying to the same location twice, but I guess I only did that for triggers and variables. I'll add one for tags too and fix the name issue. 👍

[AltamashShaikh]

Looks good now 👍