Support local perplexica AI search engine

[bart-jaskulski]

Is your feature request related to a problem? Please describe.
Recently, OSS Perplexity alternative -- (Perplexica) [https://github.com/ItzCrazyKns/Perplexica/blob/master/docs/API/SEARCH.md] released API access to search queries. Similary to existing Perplexity support, mods could be a great fit for leveraging that new feature.

Describe the solution you'd like
Sadly, Perplexica doesn't adhere to OpenAI's API spec, so a whole new custom provider is needed. It has to integrate as described (in documentation)[https://github.com/ItzCrazyKns/Perplexica/blob/master/docs/API/SEARCH.md]

Describe alternatives you've considered
Currently, an only alternative is to use it through browser.

Additional context
I'd be happy to propose an implementation if agreed on a feature.