Freqman improvements (#1276)

* Show .1 MHz in pretty freqman string

* Refactor load to user FreqmanDB

* Recon file parsing cleanup

* use strtol for parse_int

* recon file cleanup

* Fix bugs in Recon changes

* PR feedback

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Co-authored-by: kallanreed <kallanreed@noreply.github.com>

firmware/application/apps/ui_level.cpp

@@ -23,6 +23,7 @@
 
 #include "ui_level.hpp"
 #include "ui_fileman.hpp"
+#include "ui_freqman.hpp"
 #include "file.hpp"
 
 using namespace portapack;