luci-base: generalize post security token handling
luci-base: generalize post security token handling

* Add a generic helper function to check need for post / csrf token validation
* Remove custom token verification in cbi targets
* Support requiring post security depending on specific submit parameters,
  usable through post_on() action

Signed-off-by: Jo-Philipp Wich <a9275913d515487ffaed469337a530ed202da558@openwrt.org>

maxrio/luci981213,Hostle/luci,NeoRaider/luci,nmav/luci,jlopenwrtluci/luci,urueedi/luci,hnyman/luci,mumuqz/luci,cappiewu/luci,tobiaswaldvogel/luci,mumuqz/luci,ollie27/openwrt_luci,tobiaswaldvogel/luci,bittorf/luci,artynet/luci,wongsyrone/luci-1,artynet/luci,aa65535/luci,wongsyrone/luci-1,NeoRaider/luci,chris5560/openwrt-luci,nmav/luci,rogerpueyo/luci,nmav/luci,taiha/luci,cshore/luci,cappiewu/luci,teslamint/luci,kuoruan/luci,LuttyYang/luci,oneru/luci,daofeng2015/luci,981213/luci-1,Wedmer/luci,chris5560/openwrt-luci,cshore-firmware/openwrt-luci,ollie27/openwrt_luci,openwrt/luci,teslamint/luci,kuoruan/lede-luci,shangjiyu/luci-with-extra,bittorf/luci,nmav/luci,bright-things/ionic-luci,981213/luci-1,bright-things/ionic-luci,thess/OpenWrt-luci,cshore-firmware/openwrt-luci,thess/OpenWrt-luci,maxrio/luci981213,lbthomsen/openwrt-luci,openwrt-es/openwrt-luci,lbthomsen/openwrt-luci,maxrio/luci981213,981213/luci-1,openwrt-es/openwrt-luci,cshore/luci,chris5560/openwrt-luci,LuttyYang/luci,tobiaswaldvogel/luci,mumuqz/luci,chris5560/openwrt-luci,remakeelectric/luci,cappiewu/luci,artynet/luci,cshore/luci,openwrt-es/openwrt-luci,teslamint/luci,tobiaswaldvogel/luci,kuoruan/luci,aa65535/luci,taiha/luci,hnyman/luci,nmav/luci,Noltari/luci,aa65535/luci,jlopenwrtluci/luci,aa65535/luci,openwrt-es/openwrt-luci,maxrio/luci981213,cshore-firmware/openwrt-luci,Hostle/luci,kuoruan/lede-luci,kuoruan/lede-luci,shangjiyu/luci-with-extra,daofeng2015/luci,hnyman/luci,cshore-firmware/openwrt-luci,urueedi/luci,lbthomsen/openwrt-luci,bittorf/luci,cshore/luci,nmav/luci,daofeng2015/luci,rogerpueyo/luci,oneru/luci,mumuqz/luci,jlopenwrtluci/luci,bright-things/ionic-luci,981213/luci-1,artynet/luci,ollie27/openwrt_luci,Noltari/luci,cappiewu/luci,kuoruan/luci,aa65535/luci,jlopenwrtluci/luci,rogerpueyo/luci,LuttyYang/luci,artynet/luci,hnyman/luci,Hostle/luci,981213/luci-1,981213/luci-1,Wedmer/luci,tobiaswaldvogel/luci,cappiewu/luci,Hostle/luci,Noltari/luci,thess/OpenWrt-luci,teslamint/luci,teslamint/luci,taiha/luci,kuoruan/lede-luci,cshore-firmware/openwrt-luci,openwrt-es/openwrt-luci,urueedi/luci,bittorf/luci,maxrio/luci981213,rogerpueyo/luci,thess/OpenWrt-luci,hnyman/luci,kuoruan/lede-luci,shangjiyu/luci-with-extra,bright-things/ionic-luci,tobiaswaldvogel/luci,Hostle/luci,wongsyrone/luci-1,Wedmer/luci,LuttyYang/luci,daofeng2015/luci,cshore-firmware/openwrt-luci,ollie27/openwrt_luci,kuoruan/lede-luci,cappiewu/luci,ollie27/openwrt_luci,thess/OpenWrt-luci,wongsyrone/luci-1,urueedi/luci,mumuqz/luci,artynet/luci,remakeelectric/luci,ollie27/openwrt_luci,Wedmer/luci,daofeng2015/luci,nmav/luci,openwrt-es/openwrt-luci,bright-things/ionic-luci,nmav/luci,ollie27/openwrt_luci,cshore/luci,LuttyYang/luci,Wedmer/luci,lbthomsen/openwrt-luci,wongsyrone/luci-1,NeoRaider/luci,openwrt-es/openwrt-luci,shangjiyu/luci-with-extra,rogerpueyo/luci,kuoruan/lede-luci,hnyman/luci,bright-things/ionic-luci,maxrio/luci981213,wongsyrone/luci-1,oneru/luci,chris5560/openwrt-luci,kuoruan/luci,bittorf/luci,urueedi/luci,jlopenwrtluci/luci,LuttyYang/luci,shangjiyu/luci-with-extra,rogerpueyo/luci,urueedi/luci,aa65535/luci,mumuqz/luci,Wedmer/luci,981213/luci-1,tobiaswaldvogel/luci,bright-things/ionic-luci,cshore-firmware/openwrt-luci,cappiewu/luci,LuttyYang/luci,taiha/luci,NeoRaider/luci,teslamint/luci,NeoRaider/luci,kuoruan/luci,jlopenwrtluci/luci,jlopenwrtluci/luci,maxrio/luci981213,artynet/luci,bittorf/luci,oneru/luci,openwrt/luci,jlopenwrtluci/luci,openwrt/luci,lbthomsen/openwrt-luci,taiha/luci,lbthomsen/openwrt-luci,bittorf/luci,shangjiyu/luci-with-extra,NeoRaider/luci,shangjiyu/luci-with-extra,Wedmer/luci,kuoruan/luci,oneru/luci,openwrt/luci,bright-things/ionic-luci,Noltari/luci,bittorf/luci,Hostle/luci,daofeng2015/luci,Wedmer/luci,maxrio/luci981213,cappiewu/luci,Noltari/luci,tobiaswaldvogel/luci,remakeelectric/luci,Noltari/luci,openwrt/luci,hnyman/luci,oneru/luci,remakeelectric/luci,kuoruan/luci,remakeelectric/luci,openwrt/luci,wongsyrone/luci-1,cshore/luci,aa65535/luci,remakeelectric/luci,thess/OpenWrt-luci,nmav/luci,urueedi/luci,taiha/luci,kuoruan/lede-luci,daofeng2015/luci,shangjiyu/luci-with-extra,cshore/luci,Noltari/luci,mumuqz/luci,chris5560/openwrt-luci,openwrt/luci,thess/OpenWrt-luci,taiha/luci,thess/OpenWrt-luci,Noltari/luci,rogerpueyo/luci,mumuqz/luci,LuttyYang/luci,urueedi/luci,hnyman/luci,openwrt/luci,chris5560/openwrt-luci,aa65535/luci,oneru/luci,lbthomsen/openwrt-luci,chris5560/openwrt-luci,teslamint/luci,remakeelectric/luci,taiha/luci,oneru/luci,NeoRaider/luci,ollie27/openwrt_luci,Hostle/luci,openwrt-es/openwrt-luci,cshore/luci,cshore-firmware/openwrt-luci,lbthomsen/openwrt-luci,wongsyrone/luci-1,artynet/luci,teslamint/luci,rogerpueyo/luci,Noltari/luci,Hostle/luci,remakeelectric/luci,kuoruan/luci,artynet/luci,daofeng2015/luci,NeoRaider/luci