The following changes have been made:
1. Replace deprecated functions with new standard functions
2. Add corresponding MSVC functions for non-standard functions
3. Remove warnings about unsafe functions
4. CMAKE: modify find pack Libevent and openssl
5. Modify include files
6. Use pthread4W
7. Modify socket in windows
8. Add CI - github action
8.1. msvc
8.2. mingw
10. The database:
9.1. sqlite, pgsql, hiredis, mongo is test compiled.
9.2. mysql, isnot test compiled.
11. The applications、server can be compiled and run successfully!
12. Add vcpkg manifest mode in cmake.
Replace all instances of `bzero` with memset by find-replace-edit.
This is straightforward replacement which is suboptimal in a few cases
(for example we could use calloc instead of malloc+memset(0))
Inspired by #855
