Allow setup ipv6 for Port Forwards and NAT Rules if firewall4 is
used.

Add 'Restrict to address family' option for NAT Rules, if family is
any/empty , assume it is ipv4. this allow setup NAT6 rules in web ui

Signed-off-by: Chen Minqiang <ptpt52@gmail.com>

Initial changes required for firewall4 compatibility:
* depend on uc-firewall instead of firewall
* detect installed version of firewall and hide incompatible features

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Reviewed-by: Jo-Philipp Wich <jo@mein.io>

Use the new `firewall.getZoneColorStyle()` helper to apply background
color styles.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

No functional changes but required for styling rules.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Signed-off-by: Stan Grishin <stangri@melmac.net>

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Fixes: #4812
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Use a simple custom format string DSL to assemble the rule description
texts in the overview page.

Also move common code for shared, complex cbi options to the firewall
tool class.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Also resync firewall translations.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Signed-off-by: Jo-Philipp Wich <jo@mein.io>