Binary blobs containing zeros are now handled correctly.

Protobuf3 needs to be linked into the catalogue command line tools as we
use protobuf format to store checksums inside the DB.

Should be more efficient as it's a single copy operation instead of one
character at-a-time, but still requires 2 copies of the blob to convert
it from occi::Bytes to std::string (as it needs an intermediate char*
array).

It isn't necessary to serialize the protobuf to compute the serialized
length, use ByteSizeLong() instead.

Adds support for byte array columns in the DB. Implementation done for
SQLite, the others are placeholders.

- Type of checksumBlob in cta.proto should be bytes not string
- ADLER32 passed into blob as uint32_t not string (conversion to
  bytearray is now handled inside the ChecksumBlob class)

The blob is a set of type/value pairs which can be serialised to a byte
array for storage in the DB.

Redundant as it is always the same as totalBytes

* TapeFile::compressedSize is renamed to fileSize
* TapeFileWritten::compressedSize is removed, as it contains the same
  information as TapeFileWritten::size

cta-fst-gc now logs an error if it cannot list the contents of an FST filesystem or if determine the filesystem's sub directories