[FEAT] Suggested better error management

[reza0310]

PLEASE NOTE: All of this have been tested but only with CLI. I don't really know neither can test the GUI but I hope it doesn't rely on bad error management.

[reza0310]

PLEASE squash before merging. Commits c3a8deb and c962aeb don't have anything to do here and doesn't add any changes to this PR. I just screwed up a little.

[reza0310]

Also please note that PR #191 removes the same line as this PR in openEDSfile function. Shouldn't have any impact but I'd rather warn than cause problems.

[reza0310]

Files used for testing:

• Valid XDD : https://raw.githubusercontent.com/CANopenNode/CANopenEditor/refs/heads/main/Tests/minimal_project.xdd
• Invalid EDS : https://www.ati-ia.com/Products/toolchanger/software/EDSFiles/9031-05-1026.eds (error was System.Collections.Generic.KeyNotFoundException: The given key 'DeviceInfo' was not present in the dictionary.
at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key)
at libEDSsharp.EDSsharp.Loadfile (System.String filename)
at EDSSharp.Program.openEDSfile (System.String infile)
  )

[nimrof]

Looks good, thanks