Modify header separator in query to avoid issue during export

[CarolineDenis]

Fixes #4491

Checklist

• Self-review the PR after opening it to make sure the changes look good
  and self-explanatory (or properly documented)
• Add relevant issue to release milestone

Testing instructions

• run a query with Taxon Full Name by example
• verify that there is a dash and not a dot between Taxon and Full Name
• exported CSV files in Excel to ensure that the encoding is interpreted correctly

[maxpatiiuk]

this is really a microsoft's fault as they still don't use utf8 as the default
it's 2024 and utf8 should be used universally by now - https://utf8everywhere.org/
alas, we can't do much about this.
and i guess this customization would be useful for other use cases too - code looks good here, but see two comments

[maxpatiiuk]

👍

[grantfitzsimmons]

Testing instructions

• run a query with Taxon Full Name by example
• verify that there is a dash and not a dot between Taxon and Full Name

We need to also instruct the testers to open the exported CSV files in Excel to ensure that the encoding is interpreted correctly

[emenslin]

Testing instructions

• run a query with Taxon Full Name by example
• verify that there is a dash and not a dot between Taxon and Full Name
• exported CSV files in Excel to ensure that the encoding is interpreted correctly

Looks good, tried with various different fields and all seemed to show the dash and CSV files show up correctly.

[alesan99]

• verify that there is a dash and not a dot between Taxon and Full Name
• exported CSV files in Excel to ensure that the encoding is interpreted correctly

Dashes are now present 👍👍