[PepperBridgeAbstract, DealabsBridge, HotUKDealsBridge, MydealsBridge…

…] Streamlining Group Management (#4336)

* [PepperBridgeAbstract, DealabsBridge, HotUKDealsBridge, MydealsBridge] Streamlining Group Management

Since groups can change URLs, be created, or removed at the discretion
of website administrators, maintaining a valid and functional list of
groups is impractical.

Users can now enter the part of the URL that defines the group in a text
field, rather than searching through a lengthy, likely outdated list.

The way the RSS feed title is retrieved had to be adjusted accordingly.

Titles are now cached for 15 days to avoid unnecessary website access
and to prevent potential bot blocking.

Existing feeds will continue to work, as their parameters remain
unchanged; only the method for inputting them has been modified.

* [PepperBridgeAbstract, DealabsBridge, HotUKDealsBridge, MydealsBridge] Streamlining Group Management

Coding policy fixes

* [PepperBridgeAbstract, DealabsBridge, HotUKDealsBridge, MydealsBridge] Streamlining Group Management

Fix wrong comment

* [PepperBridgeAbstract, DealabsBridge, HotUKDealsBridge, MydealsBridge] Streamlining Group Management

Add Example values for Group context