Allow the use of special characters in UI filters and searches

[9joshua]

Currently the use of some characters in the UI is unsupported. A common problem with this occurs when a user adds a filter to Segments or Custom Reports which includes an unsupported character.

For example, including the > symbol in a Custom Report filter will return zero results, even if the data exists. Most users would assume there were no results and have no idea they should use the HTML entity reference > instead. This is not intuitive or efficient.

A better solution would be to detect when special characters are entered via the UI and automatically convert them to their HTML entity reference.

[michalkleiner]

This probably borders with being a bug, but if we don't have complaints every day we can probably treat it as an enhancement.

[sgiehl]

This is another symptom of #4231

[Chardonneaur]

Hi team,
I got this issue reported by a client today.
In fact, so as the German language, in Nordic countries, they are using caracters such as "ä".
Some websites are using now those caracters within the url, and indeed, yes, it does not work, so they cannot create segments, neither filters, neither using our premium features such as heatmaps.
This is problematic.