Search on package identifier should not be case sensitive

[hemmefelix]

On https://gokb.org/gokb-ui/#/search-package a search on package identifiers like ISIL is case sensitive at the moment. This leads to false negative search results (0 results) even if a package with the given ISIL is available in GOKb. The id search should be case insensitive.

Example:

• zdb-2-swi -> 0 results
• ZDB-2-SWI -> 2 results