Add manual TLE input validation
When manually adding TLEs via copy-and-paste, it's quite possible to miss white-spaces. In order to catch malformed TLEs, we should perform input validation before accepting new TLEs. This can be done by
- check the length of each TLE line (70 characters)
- try to parse the TLE with sgp4 (throws an exception in the case of a malformed TLE)