The MSVC UWP job in CI did not actually enable UWP. Fix this and
the fallouts discovered after enabling it.
- GHA/windows: make sure to enable UWP in MSVC vcpkg UWP job.
Use the CMake options and C flags already used for mingw-w64, but use
`WINAPI_FAMILY_PC_APP` instead of the deprecated `WINAPI_FAMILY_APP`.
(The former is not supported by mingw-w64, so leave it there as-is.)
Follow-up to cb22cfca69#14077
- GHA/windows: by default the MSVC UWP job became 2x-3x slower than
others after actually enabling UWP. Most of it is caused by
CMake/MSBuild automatically building full APPX containers for each
`.exe` target. This includes 21 CMake feature detections. Each
detection app is built into a 15MB APPX project, with code signing,
logos, etc. Example:
https://github.com/curl/curl/actions/runs/12056968170/job/33620610958
Disable this overhead for curl build targets via custom
`CMAKE_VS_GLOBALS` options. I've found no way to apply them to feature
detection targets, so those remain slow.
- cmake: automatically enable Unicode for UWP builds. It's required.
Also stop enabling it manually in the existing CI job.
- tests: fix `getpid()` use for Windows UWP:
```
tests\server\util.c(281,21): warning C4013: 'getpid' undefined; assuming extern returning int
```
Ref: https://github.com/curl/curl/actions/runs/12061215311/job/33632904249#step:11:38
- src/tool_doswin: disable `GetLoadedModulePaths()` for UWP.
mingw-w64 UWP was okay with this, but MS SDK headers are not.
This makes `--dump-module-paths` return empty for UWP builds.
```
src\tool_doswin.c(620,3): error C2065: 'MODULEENTRY32': undeclared identifier
src\tool_doswin.c(626,11): warning C4013: 'CreateToolhelp32Snapshot' undefined; assuming extern returning int
src\tool_doswin.c(626,36): error C2065: 'TH32CS_SNAPMODULE': undeclared identifier
src\tool_doswin.c(632,7): warning C4013: 'Module32First' undefined; assuming extern returning int
```
Ref: https://github.com/curl/curl/actions/runs/12055081933/job/33614629930#step:9:35
- examples: fix `websocket.c` to include `winsock2.h` before `windows.h`
to make it build with MSVC UWP:
```
include\curl\curl.h(143,16): error C2061: syntax error: identifier 'curl_socket_t'
include\curl\curl.h(143,16): error C2059: syntax error: ';'
include\curl\curl.h(417,52): error C2146: syntax error: missing ')' before identifier 'curlfd'
include\curl\curl.h(417,38): error C2081: 'curl_socket_t': name in formal parameter list illegal
```
Ref: https://github.com/curl/curl/actions/runs/12055317910/job/33615644427#step:14:126
- GHA/windows: silence linker warning with MSVC UWP builds:
```
LINK : warning LNK4075: ignoring '/INCREMENTAL' due to '/OPT:ICF' specification
```
Ref: https://github.com/curl/curl/actions/runs/12055696808/job/33616629610#step:11:38
- GHA/windows: set `/INCREMENTAL:NO` for all MSVC jobs to improve
performance a little.
- cmake: show `UWP` platform flag.
Ref: #15652Closes#15657
- `websocket.c`: use `Sleep()` on Windows.
`sleep()` and `unistd.h` are not available in MSVC.
- `http2-upload.c`: use local `gettimeofday()` implementation when
compiled with MSVC.
(Alternate solution is to disable the trace function for MSVC.)
Public domain code copied and adapted from libssh2:
e973493f99/src/misc.c (L719-L743)
- silence compiler warning for deprecated `inet_addr()`.
Also drop duplicate winsock2 include.
```
curl\docs\examples\externalsocket.c(125,32): error C2220: the following warning is treated as an error [curl\bld\docs\examples\curl-example-externalsocket.vcxproj]
curl\docs\examples\externalsocket.c(125,32): warning C4996: 'inet_addr': Use inet_pton() or InetPton() instead or define _WINSOCK_DEPRECATED_NO_WARNINGS to disable deprecated API warnings [curl\bld\docs\examples\curl-example-e
```
Ref: https://github.com/curl/curl/actions/runs/9227337318/job/25389073450#step:4:95
- silence an MSVC compiler warning. This is in conflict with `checksrc`
rules, so silence the rule in favour of the warning-free C syntax.
```
curl\docs\examples\multi-legacy.c(152,1): error C2220: the following warning is treated as an error [curl\bld\docs\examples\curl-example-multi-legacy.vcxproj]
curl\docs\examples\multi-legacy.c(152,1): warning C4706: assignment within conditional expression [curl\bld\docs\examples\curl-example-multi-legacy.vcxproj]
```
Ref: https://github.com/curl/curl/actions/runs/9227337318/job/25389073450#step:4:226
- do not use `sys/time.h` and `unistd.h` in Windows builds.
Some of these includes look unnecessary. Subject to another PR.
Cherry-picked from #13766Closes#13771
