Clang/Clazy pass over AzCore (#5045)

* Multiple cleanups ( tidy etc. )

Coalesce nested namespaces.

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* Multiple cleanups ( tidy etc. ) cntd.

Converted Uuid into POD ( defaulted the constructor )
Add `&/const &` to `for` loops that benefit from their use
Some Qt optimizations ( string ref, prevent container detaches, etc. )
Replace `::bind` in a few places.
Replaced the use of AZ_CRC with AZ_CRC_CE in a few places.
Replace a few `typedef`s with `using`s

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* Linux compilation fix.

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* Apply review suggestions.

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* Fix vs2019 build

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* Small clang re-format in StringFunc.cpp

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

* Apply reviewer's suggestions.

Signed-off-by: nemerle <96597+nemerle@users.noreply.github.com>

Code/Editor/AssetImporter/AssetImporterManager/AssetImporterManager.cpp

@@ -140,7 +140,7 @@ bool AssetImporterManager::OnBrowseFiles()
     bool encounteredCrate = false;
     QStringList invalidFiles;
 
-    for (QString path : fileDialog.selectedFiles())
+    for (const QString& path : fileDialog.selectedFiles())
     {
         QString fileName = GetFileName(path);
         QFileInfo info(path);