Add logic for setting DRACO_ROUNDOFF_MODE for FMA CPP macro. (#1093)

* Add logic for setting DRACO_ROUNDOFF_MODE for FMA CPP macro.

+ Add build system logic that allows us to toggle between *fast* and *accurate* FMA modes.  In
  general, *accurate* is required for CI and regression testing while *fast* is enabled for
  releases.
+ Related to #6
+ Added a new CMake option `DRACO_ROUNDOFF_MODE` that defaults to `ACCURATE`.
+ This option is published in `draco-config.cmake` and `ds++/config.h` so other projects are aware
  of Draco's run mode for FMA. The cmake file provide information to client build systems.  The
  header file provides information to client source code.
+ Release scripts were updated so that *fast* FMA is enabled for releases.

* Fix some formatting issues.

+ The `cmake-format` program damaged some text blocks that needed manual cleaning up.
+ Update the new PR templte so that it points to re-git instead of redmine.

* mark shell script +x

.github/PULL_REQUEST_TEMPLATE

@@ -6,7 +6,7 @@
 
 * detail 1, refs #2 (github number)
 * detail 2
-* [Fixes Redmine Issue #3](https://rtt.lanl.gov/redmine/issues/3)
+* [Fixes re-git issue #3](https://re-git.lanl.gov/draco/draco/-/issues/3)
 
 ### Description of changes