doc: Scrubbed ALL sensor library descriptions

In an effort to clean-up and standardize UPM library
documentation, this commit updates (and in most cases,
unifies) the CMake description string AND CXX header
@comname string.

Strings were taken from datasheets when possible, spelling
mistakes were addressed, copy/paste errors where fixed,
Title Case was used, etc.

    * Tested/updated/added @web tags
    * Added/updated invalid sensor images
    * Added/updated @man tags, added missing manufacturers

Signed-off-by: Noel Eck <noel.eck@intel.com>

src/ad8232/CMakeLists.txt

@@ -1,5 +1,5 @@
 upm_mixed_module_init (NAME ad8232
-    DESCRIPTION "Single lead heart rate monitor"
+    DESCRIPTION "Single Lead Heart Rate Monitor"
     C_HDR ad8232.h
     C_SRC ad8232.c
     CPP_HDR ad8232.hpp

src/ad8232/ad8232.hpp

@@ -43,7 +43,7 @@ namespace upm {
   /**
    * @library ad8232
    * @sensor ad8232
-   * @comname AD8232 Heart Rate Monitor
+   * @comname Single Lead Heart Rate Monitor
    * @type medical
    * @man sparkfun
    * @web https://www.sparkfun.com/products/12650