Matching the RNA id's to the search pattern is slow because
of the function `fnmatchcase`. This patch first checks the string
prefix without any special characters used by fnmatch,
if the `startswith` check fails, there is no need to check `fnmatchcase`.
Before the optimization, an online manual lookup took about 400ms
which is quite noticeable, with this patch applied it's under 10ms.
Ref !104581.