SearchIO.QueryResult object does not have an 'accession' attribute all the time when parsing hmmer3-text records

When parsing hmmer3-text records, the `QueryResult` objects returned only have an `accession` attribute when there's an `Accession:` line in the corresponding hmmer file.
This behaviour is at odds with the behaviour on e.g. hmmsearch3-domtab files, where there is always an `accession` attribute on the `QueryResult`, but it may be `-` if not set.

See the zip file below for a reproducer.

[example.zip](https://github.com/biopython/biopython/files/771069/example.zip)