Add support for SKCC logging

[alduhoo]

Add support for SKCC. Adds an extension that downloads member data and autocompletes the name/QTH/number after entering the callsign.

Also added typescript support.

[sd]

I'm not against TypeScript, but right now the rest of the codebase is all in plain JS, and this PR randomly changes lots of files to be TS, even outside of the skcc extension.

I think the easiest thing right now is to just use plain JS.

Also, the method to load data files changed from RNFetchBlob.fetch() to our own fetchAndProcessURL which hides some of the details, and implements ETag caching. Look at the data file logic for other extensions for reference.

[alduhoo]

I'm not against TypeScript, but right now the rest of the codebase is all in plain JS, and this PR randomly changes lots of files to be TS, even outside of the skcc extension.

I think the easiest thing right now is to just use plain JS.

Also, the method to load data files changed from RNFetchBlob.fetch() to our own fetchAndProcessURL which hides some of the details, and implements ETag caching. Look at the data file logic for other extensions for reference.

I think adopting TypeScript would be a good move as it will allow developers to propose changes faster and makes it easier to navigate the codebase. One of the advantages of TypeScript is that you can gradually migrate the code, so you don't have to migrate it all at once. But that could probably be done as a separate PR.

I'll remove the typescript changes and update the file loading to the latest,