Merge query parameters back after Tweakwise Personal Merchandier Refresh

[Beagon]

There is an issue with the refresh the Personal Merchandiser does and query parameters used by marketing teams to track clicks from newsletters/blogs etc.

This reads the query parameters if there were any on the PM refresh (and other unintended refreshes)

[ah-net]

@Beagon Thx for the pull request.

What is the use case for the flip function you've added? Why do they need to be flipped?

[Beagon]

They have to be flipped because otherwise the function wouldn't merge in the right priority in some instances, for example:

Lets say you are on the following page:
https://example.io/category?p=3

And you use the pagination to go to page 4. If you don't flip the priority it would not update the page number in the URL since.

We would've expected https://example.io/category?p=4 but it remained https://example.io/category?p=3. Of course the rest of the page was correct, just the updated URL by the JS wasn't correct.

[ah-net]

@Beagon I've added an change to make sure that the page paremeter is an int, to prevent xss issues

[ah-net]

@Beagon This pull request seems to be causes this issue #119. To fix #119 we will be reverting this change unless you have another solution for this, or an good explanation as to why this change is needed.

The most marketing tools i've seen use the parameter to set an cookie. So it's not important that on an page request the parameter still persists.

[Beagon]

As I'm not currently working with Magento I do not have time to propose a different solution for this issue. Feel free to reverse the change.