Use memory mapped files for streaming uploads (Azure#19635)

* Use memory mapped files for streaming uploads

This is to avoid extra allocations and heap fragmentation.
Removed transfer manager and related code.

* clarify change description

* fix generic type constraint

* refinement

* use MAP_PRIVATE on Un*x

* log instead of panic when unmapping section fails

* revert back to Concurrency but keep doc change

* fix copy/paste

* remove unused import

* panic on failure to free buffer

Author: jhendrixMSFT

sdk/storage/azblob/CHANGELOG.md

@@ -24,8 +24,9 @@
 
 ### Other Changes
 
-* Avoid allocations when storing/fetching a slice via sync.Pool.
 * Added some missing public surface area in the `container` and `service` packages.
+* The `UploadStream()` methods now use anonymous memory mapped files for buffers in order to reduce heap allocations/fragmentation.
+  * The anonymous memory mapped files are typically backed by the page/swap file, multiple files are not actually created.
 
 ## 0.5.1 (2022-10-11)