luci-mod-network: add support for creating cname records

[arbolitoloco1]

I used the MX and SRV tabs as templates to create a new tab where users can create cname records in dnsmasq, using the cname and target options.

[ErwanMAS]

@hnyman @jow- @Zeranoe @feckert hey can someone take a look on this , this is very useful when you want to rewrite/shadow public DNS .

from DNSMASQ man pages :

addresses in /etc/hosts will "shadow" different addresses for the same names in the upstream DNS, so "mycompany.com 1.2.3.4" in /etc/hosts will ensure that queries for "mycompany.com" always return 1.2.3.4 even if queries in the upstream DNS would otherwise return a different address. There is one exception to this: if the upstream DNS contains a CNAME which points to a shadowed name, then looking up the CNAME through dnsmasq will result in the unshadowed address associated with the target of the CNAME. To work around this, add the CNAME to /etc/hosts so that the CNAME is shadowed too.

[systemcrash]

Shouldn't that be like so?:

			_('Set an alias for a hostname.'));

[arbolitoloco1]

Sorry, yeah, I think so. just fixed it!

[arbolitoloco1]

This is how it looks on my router currently, with the underscore added.

[arbolitoloco1]

I messed up in a horrendous way but I think this is good now (unless the test build fails). Sorry for all the mess

[systemcrash]

Just for my own edification, how does one push zero commits? 🤔

[arbolitoloco1]

I did:
git reset --soft HEAD~1, where 1 means remove 1 commit
git push origin +patch-4

found it on https://stackoverflow.com/questions/448919/how-can-i-remove-a-commit-on-github in the middle of my desperation lol

[systemcrash]

Oh, now I know 😁