Increase tagname character limit from 32 to 64 characters or more

We are using Spectrum Discover in a research and academia environment. When
looking towards how we will curate and manage tags as the number of included
projects grows, we see that the tagname limit of 32 characters is a problem.
When extracting exif-metadata from images, there are already some fields that
are approaching that limit. With additions of research-field-specific tags
and adminstrative and publication-related tags, there is a necessity for
some sort of structure and naming conventions for tags.

Since the tag structure in Spectrum Discover is flat, the most direct solution
to create structure is through the use of prefixes. 32 characters is too low
to do this in a reasonable manner. If you rely on only two prefix-levels,
say "pre1_pre2_tagname", you've already restricted all tagnames to only
20-22 characters. Unless you use hashes or some numeric names, this is not
scalable to large amounts of tags. And if you do have to resort to hashes or
numeric tagnames, tags are no longer "human-readable". This necessitates a
translation layer between spectrum discover and any outside resources.
We would like to avoid this. The problem could be somewhat alleviated by using
numbers as prefixes, but even this reduces readability, and still requires
some translation to be done.

We would like to see the tagname character limit increased to 128
characters. 128 characters is roughly 18-20 regular length words,
and we believe only extreme edge-cases would approach the tagname limit
in this case. 64 characters is a definitive improvement over 32 characters,
and may be considered the smallest viable amount.
Of course, more than 128 characters is also fine, but we do not have insight
into how database-related performance might be affected here.