dnsdist: Add a DynBlockRulesGroup:removeRange() binding

[rgacogne]

Short description

This adds the ability to remove an existing range from the list of existing included/excluded ranges.

Checklist

I have:

• read the CONTRIBUTING.md document
• compiled this code
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)

[Habbie]

code looks good, one doc nit

[rgacogne]

Rebased on master.

[coveralls]

Pull Request Test Coverage Report for Build 6575778053

• 1 of 24 (4.17%) changed or added relevant lines in 3 files are covered.
• 35 unchanged lines in 7 files lost coverage.
• Overall coverage decreased (-0.02%) to 57.468%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pdns/iputils.hh	0	5	0.0%
pdns/dnsdist-dynblocks.hh	0	6	0.0%
pdns/dnsdist-lua-inspection.cc	1	13	7.69%

Files with Coverage Reduction	New Missed Lines	%
pdns/backends/gsql/gsqlbackend.hh	1	96.57%
pdns/dnsdist.cc	2	70.79%
pdns/tcpiohandler.cc	2	66.65%
pdns/recursordist/taskqueue.hh	3	71.43%
pdns/recursordist/rec-zonetocache.cc	4	50.1%
pdns/recursordist/rec-main.cc	8	35.11%
pdns/recursordist/rec-taskqueue.cc	15	30.8%

Totals
Change from base Build 6574953728:	-0.02%
Covered Lines:	105349
Relevant Lines:	152672

---

💛 - Coveralls