PatternClips now use startTimeOffset, too, and can be resized on their start

[ToastedSadWitch]

I checked the gui part, playback, export, copying and storing.
When dropping a pattern clip with startTimeOffset into another pattern clip, the startTimeOffset is currently not copied. If this is no wanted behaviour, please tell me, so I can try to fix it.
Also the behaviour of resizing the start is faulty sometimes when colliding with the start of the song editor (clip may grow or there is a padding sometimes). As this also happens on the sample track, it seems to be a general deal with ResizeLeft action.
This commit is for issue #6346.

[superpaik]

Tested on W10-64. It works ok.
I was not able to reproduce that "When dropping a pattern clip with startTimeOffset into another pattern clip, the startTimeOffset is currently not copied. If this is no wanted behaviour, please tell me, so I can try to fix it." In my case, when dropped over another existing clip, it's replaced ok. In any case, I think that's the desired behaviour.

[DomClark]

Thanks for the pull request! This looks really useful. I've left a few comments on the code - feel free to quibble them if you think I'm talking nonsense, or ask for more detail if I haven't been clear enough.

[ToastedSadWitch]

build fails should be fixed with this

[Veratil]

Just some naming thoughts. Feel free to ignore for merge.

[ToastedSadWitch]

Final fix from my side.

[ToastedSadWitch]

CMake Error at scripts/cmake/vcpkg_download_distfile.cmake:32 (message):

Failed to download file with error: 1
If you use a proxy, please check your proxy setting. Possible causes are:

1. You are actually using an HTTP proxy, but setting HTTPS_PROXY variable
   to https://address:port. This is not correct, because https:// prefix
   claims the proxy is an HTTPS proxy, while your proxy (v2ray, shadowsocksr
   , etc..) is an HTTP proxy. Try setting http://address:port to both
   HTTP_PROXY and HTTPS_PROXY instead.

2. You are using Fiddler. Currently a bug ([vcpkg-tool] pr 49 cause proxy no use microsoft/vcpkg#17752)
   will set HTTPS_PROXY to https://fiddler_address:port which lead to problem 1 above.
   Workaround is open Windows 10 Settings App, and search for Proxy Configuration page,
   Change http=address:port;https=address:port to address, and fill the port number.

3. Your proxy's remote server is out of service.

In future vcpkg releases, if you are using Windows, you no longer need to set
HTTP(S)_PROXY environment variables. Vcpkg will simply apply Windows IE Proxy
Settings set by your proxy software. See (microsoft/vcpkg-tool#49)
and (microsoft/vcpkg-tool#77)

Otherwise, please submit an issue at https://github.com/Microsoft/vcpkg/issues

Call Stack (most recent call first):
scripts/cmake/vcpkg_download_distfile.cmake:273 (z_vcpkg_download_distfile_show_proxy_and_fail)
scripts/cmake/vcpkg_acquire_msys.cmake:26 (vcpkg_download_distfile)
scripts/cmake/vcpkg_acquire_msys.cmake:67 (z_vcpkg_acquire_msys_download_package)
scripts/cmake/vcpkg_acquire_msys.cmake:186 (z_vcpkg_acquire_msys_declare_package)
scripts/cmake/vcpkg_configure_make.cmake:212 (vcpkg_acquire_msys)
ports/libiconv/portfile.cmake:29 (vcpkg_configure_make)
scripts/ports.cmake:147 (include)

[Veratil]

@ToastedSadWitch since the vcpkg error isn't something on our side we can ignore that. :)