Refactor pgp_key_search_t #597

Job	Run time
Windows-2019 [arch x64, toolset v142, backend botan, build shared libs off, use CMake prefix path on, sanitizers off]	17m 34s
Windows-2019 [arch x64, toolset v142, backend botan, build shared libs off, use CMake prefix path off, sanitizers off]	17m 59s
Windows-2019 [arch x64, toolset v142, backend openssl, build shared libs off, use CMake prefix path on, sanitizers off]	12m 20s
Windows-2019 [arch x64, toolset v142, backend openssl, build shared libs off, use CMake prefix path off, sanitizers off]	14m 21s
Windows-2019 [arch x64, toolset ClangCL, backend botan, build shared libs off, use CMake prefix path on, sanitizers off]	14m 57s
Windows-2019 [arch x64, toolset ClangCL, backend botan, build shared libs off, use CMake prefix path off, sanitizers off]	18m 5s
Windows-2019 [arch x64, toolset ClangCL, backend openssl, build shared libs off, use CMake prefix path on, sanitizers off]	13m 15s
Windows-2019 [arch x64, toolset ClangCL, backend openssl, build shared libs off, use CMake prefix path off, sanitizers off]	16m 53s
Windows-2019 [arch x64, toolset v142, backend botan, build shared libs off, use CMake prefix path off, sanitizers on]	31m 2s
Windows-2019 [arch Win32, toolset ClangCL, backend botan, build shared libs off, use CMake prefix path on, sanitizers off]	21m 48s
Windows-2019 [arch Win32, toolset v142, backend openssl, build shared libs off, use CMake prefix path off, sanitizers off]	20m 24s
	3h 18m 38s

Provide feedback