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/waterlevel/CMakeLists.txt

@@ -1,5 +1,5 @@
 set (libname "waterlevel")
-set (libdescription "Waterlevel sensor module")
+set (libdescription "Water Level Sensor")
 set (module_src ${libname}.cxx)
 set (module_hpp ${libname}.hpp)
 upm_module_init(mraa)

src/waterlevel/waterlevel.hpp

@@ -34,7 +34,7 @@ namespace upm {
   /**
    * @library waterlevel
    * @sensor waterlevel
-   * @comname Grove Water Level Sensor
+   * @comname Water Level Sensor
    * @type liquid
    * @man seeed
    * @con gpio