file_manager: trap the exception if the claim is not a stream

If `claim` is not a stream, the line `claim.stream.source.bt_infohash`
will raise a `ValueError` exception because `claim.stream`
does not contain a valid object.

This will happen if we try to download a claim
that is in fact a `collection` (a playlist).
```
lbrynet get collection-music
```

Since at the moment we don't trap this exception, it prints
the entire trace of the exception.
```
Traceback (most recent call last):
  File "/opt/git/lbry-sdk/lbry/file/file_manager.py", line 117, in download_from_uri
    if claim.stream.source.bt_infohash:
  File "/opt/git/lbry-sdk/lbry/schema/claim.py", line 55, in stream
    return Stream(self)
  File "/opt/git/lbry-sdk/lbry/schema/claim.py", line 108, in __init__
    self.message = self.claim.get_message(self.claim_type)
  File "/opt/git/lbry-sdk/lbry/schema/claim.py", line 46, in get_message
    raise ValueError(f'Claim is not a {type_name}.')
```

Therefore we will raise `InvalidStreamURLError` if `claim.is_collection` is True
or if `claim.is_stream` is False.

Later on the code we handle this `InvalidStreamURLError` exception
to show the appropriate message.
```
WARNING  lbry.file.file_manager:258: Failed to download collection-music:
Invalid LBRY stream URL: 'collection-music'
WARNING  lbry.extras.daemon.daemon:1114:
Error downloading collection-music: Claim is not a stream.
```

lbry/file/file_manager.py

@@ -114,6 +114,11 @@ async def download_from_uri(self, uri, exchange_rate_manager: 'ExchangeRateManag
             resolved_time = self.loop.time() - start_time
             await self.storage.save_claim_from_output(self.wallet_manager.ledger, txo)
 
+            if claim.is_collection:
+                raise InvalidStreamURLError(uri)
+            if not claim.is_stream:
+                raise InvalidStreamURLError(uri)
+
             ####################
             # update or replace
             ####################