[nsapi] Added support for multiple results in a dns-query
[nsapi] Added support for multiple results in a dns-query

Internal API changes:
+ nsapi_dns_query_multiple

Note, dns_query_multiple takes a buffer of nsapi_addr_t to fill. This is
less dynamic than the linked-list method used in linux's gethostbyname,
but is easier to manage and more constrained.

c1728p9/mbed-os,adustm/mbed,jeremybrodt/mbed,bulislaw/mbed-os,cvtsi2sd/mbed-os,tung7970/mbed-os-1,ryankurte/mbed-os,fahhem/mbed-os,maximmbed/mbed,infinnovation/mbed-os,theotherjimmy/mbed,jeremybrodt/mbed,ryankurte/mbed-os,theotherjimmy/mbed,mikaleppanen/mbed-os,CalSol/mbed,catiedev/mbed-os,bcostm/mbed-os,NXPmicro/mbed,mbedmicro/mbed,svogl/mbed-os,NXPmicro/mbed,tung7970/mbed-os,CalSol/mbed,arostm/mbed-os,andcor02/mbed-os,fvincenzo/mbed-os,YarivCol/mbed-os,c1728p9/mbed-os,svogl/mbed-os,nvlsianpu/mbed,c1728p9/mbed-os,cvtsi2sd/mbed-os,mikaleppanen/mbed-os,kl-cruz/mbed-os,betzw/mbed-os,mazimkhan/mbed-os,Archcady/mbed-os,HeadsUpDisplayInc/mbed,andcor02/mbed-os,Archcady/mbed-os,tung7970/mbed-os-1,c1728p9/mbed-os,mikaleppanen/mbed-os,adamgreen/mbed,j-greffe/mbed-os,cvtsi2sd/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,c1728p9/mbed-os,ryankurte/mbed-os,mbedmicro/mbed,mazimkhan/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,bcostm/mbed-os,fahhem/mbed-os,mmorenobarm/mbed-os,j-greffe/mbed-os,cvtsi2sd/mbed-os,nvlsianpu/mbed,monkiineko/mbed-os,arostm/mbed-os,svogl/mbed-os,pradeep-gr/mbed-os5-onsemi,monkiineko/mbed-os,tung7970/mbed-os-1,pradeep-gr/mbed-os5-onsemi,karsev/mbed-os,fvincenzo/mbed-os,adamgreen/mbed,j-greffe/mbed-os,YarivCol/mbed-os,theotherjimmy/mbed,RonEld/mbed,screamerbg/mbed,fvincenzo/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,nRFMesh/mbed-os,ryankurte/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,adustm/mbed,bulislaw/mbed-os,svogl/mbed-os,bcostm/mbed-os,adustm/mbed,svastm/mbed,catiedev/mbed-os,jeremybrodt/mbed,kjbracey-arm/mbed,maximmbed/mbed,nvlsianpu/mbed,nRFMesh/mbed-os,svogl/mbed-os,tung7970/mbed-os,fahhem/mbed-os,mazimkhan/mbed-os,CalSol/mbed,cvtsi2sd/mbed-os,HeadsUpDisplayInc/mbed,andreaslarssonublox/mbed,catiedev/mbed-os,svastm/mbed,monkiineko/mbed-os,mikaleppanen/mbed-os,Archcady/mbed-os,maximmbed/mbed,theotherjimmy/mbed,mmorenobarm/mbed-os,catiedev/mbed-os,ryankurte/mbed-os,j-greffe/mbed-os,j-greffe/mbed-os,bcostm/mbed-os,mazimkhan/mbed-os,kl-cruz/mbed-os,mbedmicro/mbed,catiedev/mbed-os,HeadsUpDisplayInc/mbed,maximmbed/mbed,mmorenobarm/mbed-os,karsev/mbed-os,fanghuaqi/mbed,karsev/mbed-os,pradeep-gr/mbed-os5-onsemi,screamerbg/mbed,andcor02/mbed-os,andcor02/mbed-os,tung7970/mbed-os,bcostm/mbed-os,screamerbg/mbed,arostm/mbed-os,karsev/mbed-os,nvlsianpu/mbed,adustm/mbed,nRFMesh/mbed-os,NXPmicro/mbed,fvincenzo/mbed-os,adustm/mbed,andreaslarssonublox/mbed,RonEld/mbed,screamerbg/mbed,svastm/mbed,andreaslarssonublox/mbed,infinnovation/mbed-os,kjbracey-arm/mbed,fahhem/mbed-os,netzimme/mbed-os,netzimme/mbed-os,CalSol/mbed,tung7970/mbed-os,fanghuaqi/mbed,ryankurte/mbed-os,screamerbg/mbed,bulislaw/mbed-os,adamgreen/mbed,andreaslarssonublox/mbed,infinnovation/mbed-os,adamgreen/mbed,infinnovation/mbed-os,mbedmicro/mbed,c1728p9/mbed-os,CalSol/mbed,fahhem/mbed-os,netzimme/mbed-os,monkiineko/mbed-os,YarivCol/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,fanghuaqi/mbed,fahhem/mbed-os,HeadsUpDisplayInc/mbed,tung7970/mbed-os-1,RonEld/mbed,kjbracey-arm/mbed,pradeep-gr/mbed-os5-onsemi,svastm/mbed,NXPmicro/mbed,monkiineko/mbed-os,jeremybrodt/mbed,svogl/mbed-os,bcostm/mbed-os,Archcady/mbed-os,kl-cruz/mbed-os,kl-cruz/mbed-os,karsev/mbed-os,monkiineko/mbed-os,svastm/mbed,netzimme/mbed-os,RonEld/mbed,kjbracey-arm/mbed,CalSol/mbed,betzw/mbed-os,adamgreen/mbed,cvtsi2sd/mbed-os,nvlsianpu/mbed,fanghuaqi/mbed,adamgreen/mbed,arostm/mbed-os,mmorenobarm/mbed-os,mmorenobarm/mbed-os,NXPmicro/mbed,andreaslarssonublox/mbed,infinnovation/mbed-os,andcor02/mbed-os,theotherjimmy/mbed,nRFMesh/mbed-os,infinnovation/mbed-os,betzw/mbed-os,betzw/mbed-os,betzw/mbed-os,nvlsianpu/mbed,adustm/mbed,mazimkhan/mbed-os,NXPmicro/mbed,maximmbed/mbed,tung7970/mbed-os-1,nRFMesh/mbed-os,maximmbed/mbed,pradeep-gr/mbed-os5-onsemi,YarivCol/mbed-os,bulislaw/mbed-os,YarivCol/mbed-os,fvincenzo/mbed-os,mbedmicro/mbed,bulislaw/mbed-os,mmorenobarm/mbed-os,andcor02/mbed-os,j-greffe/mbed-os,HeadsUpDisplayInc/mbed,netzimme/mbed-os,mikaleppanen/mbed-os,arostm/mbed-os,Archcady/mbed-os,HeadsUpDisplayInc/mbed,jeremybrodt/mbed,kl-cruz/mbed-os,betzw/mbed-os,RonEld/mbed,karsev/mbed-os,kl-cruz/mbed-os,netzimme/mbed-os,bulislaw/mbed-os,YarivCol/mbed-os,mazimkhan/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,theotherjimmy/mbed,fanghuaqi/mbed,pradeep-gr/mbed-os5-onsemi,Archcady/mbed-os,catiedev/mbed-os,nRFMesh/mbed-os,tung7970/mbed-os,mikaleppanen/mbed-os,screamerbg/mbed,arostm/mbed-os,RonEld/mbed