Added support for detecting bots through client-hints

[sanchezzzhak]

for matomo, you will need to add a new HTTP_X_CLIENT key
https://github.com/matomo-org/matomo/blob/d1eaaca1b7abdddea15ff8d1d8e2075b6f92c672/core/Http.php#L996-L1012

[!] this PR is worth viewing about when we have more bots through the xClient header.

[liviuconcioiu]

@sanchezzzhak I have something to add:

1. Can you also include the HTTP_FROM header? According to https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/From this one is a must for any crawler. So, if this header is present it should be detected as Generic bot for example.
2. Here are some HTTP_FROM values that should be added, to be detected as specific bots:

googlebot(at)googlebot.com
bingbot(at)microsoft.com
[email protected]
[email protected]
[email protected]

[sanchezzzhak]

@liviuconcioiu Perhaps the implementation of HTTP_FROM should be added separately, since this PR is in limbo.
It would be good to have approximate statistics before implementing new features.