Introduce dedicated case insensitive match operator

[Crited]

Is your feature request related to a problem? Please describe.

A environment might use variables like host.vars.contacts. Logging into Icinga Web 2 via e.g. Active Directory is case-insensitive. Comparing the current username to a variable like that is possible through the use of user.local_name.

The filter of a role might look like this:

host.vars.contacts[*]~$user.local_name$

For a value of FooBar for host.vars.contacts and fooBar for user.local_name this would evaluate to false.

While one could influence the content of host.vars.contacts to be lowercase at all times and force users to use lowercase logins so user.local_name. I reckon a case insensitive match is useful in more than just this scenario.

Describe the solution you'd like

Introduce a dedicated case insensitive match operator. (Force case insensitive)
Maybe something like this? =~

host.vars.contacts[*]=~$user.local_name$

For a value of FooBar for host.vars.contacts and fooBar for user.local_name this would evaluate to true.

Describe alternatives you've considered

Make implicit case insensitive match through wildcards work for macros?

host.vars.contacts[*]~*"$user.local_name$"*
host.vars.contacts[*]~*$user.local_name$*

Additional context

Apparently this used to work with monitoring over icingadb:

_host.vars.contacts=*"$user.local_name$"*