You know, you do not need to go into the database, you can go through the developer module and recompile module by module or all in one, it is done for that.
For example, you have finished (or even partially) to translate the xml file of the module "photo", you overwrite the original file and you recompile the module "photo" in your language.
This has the effect of resetting all the keys contained and exactly as in your xml file that you have just translated.
So you can from the english file and rename it, I take the example for French, fr.xml.
And the first two lines of the file like this:
<? xml version = "1.0" encoding = "utf-8"?>
<resources name = "en" flag = "en" title = "french">
But apparently you did it.
WARNING: Just do not go wrong with the "recompile" button that will remove all your custom keys and that's very unfortunate.
For the icon it is not mandatory, but the ideal is an icon.svg You can start from a .png and rework it and convert it with Inskape
Here may be some useful information for you.
I know it's a tedious job and the good news is that you have to update it for important updates.
Well done, you did well ;-)