Replace dependency on boost with a custom small vector (#13716)

This replaces ~70k LOC (parts of boost, 1/4th of the code in this project)
with ~700 LOC (`small_vector.h`). By replacing boost, we simplify future
maintenance and improve compile times.

## Validation Steps Performed
* New and existing unit tests are ok ✅
* Various common VT applications run fine in debug mode OpenConsole ✅

.github/actions/spelling/allow/allow.txt

@@ -57,6 +57,7 @@ locl
 lorem
 Lorigin
 maxed
+minimalistic
 mkmk
 mnt
 mru

NOTICE.md

@@ -215,39 +215,6 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 ```
 
-
-## boost
-
-**Source**: [https://github.com/boostorg/boost](https://github.com/boostorg/boost)
-
-### License
-
-```
-Boost Software License - Version 1.0 - August 17th, 2003
-
-Permission is hereby granted, free of charge, to any person or organization
-obtaining a copy of the software and accompanying documentation covered by
-this license (the "Software") to use, reproduce, display, distribute,
-execute, and transmit the Software, and to prepare derivative works of the
-Software, and to permit third-parties to whom the Software is furnished to
-do so, all subject to the following:
-
-The copyright notices in the Software and this entire statement, including
-the above license grant, this restriction and the following disclaimer,
-must be included in all copies of the Software, in whole or in part, and
-all derivative works of the Software, unless such copies or derivative
-works are solely in the form of machine-executable object code generated by
-a source language processor.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
-SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
-FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
-ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-DEALINGS IN THE SOFTWARE.
-```
-
 ## PCG Random Number Generation
 
 **Source**: [https://github.com/imneme/pcg-cpp](https://github.com/imneme/pcg-cpp)