Appveyor: Copy required DLLs to test and app

[teor2345]

Copy required DLLs to test and app, before running tor's tests.

This ensures that tor.exe and test*.exe use the correct version of each
DLL. This fix is not required, but we hope it will avoid DLL search
issues in future.

Closes bug 33673; bugfix on 0.3.4.2-alpha.

[coveralls]

Pull Request Test Coverage Report for Build 8496

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1243 unchanged lines in 34 files lost coverage.
• Overall coverage decreased (-1.7%) to 59.217%

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Files with Coverage Reduction	New Missed Lines	%
src/feature/dirclient/dirclient.c	1	18.5%
src/feature/hs/hs_service.c	1	73.16%
src/feature/nodelist/nodelist.c	1	61.26%
src/core/or/circuitlist.c	2	55.45%
src/core/or/policies.c	2	84.6%
src/feature/dircache/consdiffmgr.c	2	90.06%
src/feature/nodelist/microdesc.c	2	73.12%
src/feature/relay/router.c	2	35.2%
src/feature/rend/rendcache.c	2	92.89%
src/lib/container/buffers.c	2	91.2%

Totals
Change from base Build 8488:	-1.7%
Covered Lines:	43335
Relevant Lines:	73180

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💛 - Coveralls