Provisioning: move Conan manifests to common directory

We need to use x86 packages from qtci-windows-10-x86_64 configuration,
so splitting Conan manifests by configuration is not a good idea anymore.

Task-number: QTBUG-61829
Change-Id: I8b2fc00865cce372ca6b5ec75b4775d345d0d18f
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

coin/provisioning/common/03-conan.ps1

@@ -32,11 +32,12 @@ function Run-Conan-Install
         $extraArgs = "-s compiler.libcxx=$($CompilerLibcxx)"
     }
 
+    $manifestsDir = "$PSScriptRoot\conan_manifests"
+
     Get-ChildItem -Path "$ConanfilesDir\*.txt" |
     ForEach-Object {
         $conanfile = $_.FullName
         $outpwd = "C:\Utils\conanbuildinfos\$($BuildinfoDir)\$($_.BaseName)"
-        $manifestsDir = "$($_.DirectoryName)\$($_.BaseName).manifests"
         New-Item $outpwd -Type directory -Force
 
         $process = Start-Process-Logged `

coin/provisioning/qtci-windows-10-x86_64/conanfiles/qtwebkit.manifests/icu/57.1/vitallium/stable/export/conanmanifest.txt

@@ -1,2 +0,0 @@
-1482492127
-conanfile.py: 7edc28cf26a4c3acd9b1c9f08ea8cba3

coin/provisioning/qtci-windows-10-x86_64/conanfiles/qtwebkit.manifests/libxml2/2.9.4/vitallium/stable/export/conanmanifest.txt

@@ -1,2 +0,0 @@
-1482493404
-conanfile.py: 4c879159bebcecec85173f085cd4c3c7

coin/provisioning/qtci-windows-10-x86_64/conanfiles/qtwebkit.manifests/libxslt/1.1.29/vitallium/stable/export/conanmanifest.txt

@@ -1,2 +0,0 @@
-1478438034
-conanfile.py: 2472a82109b2d59062d3e50a54d08a4a