Fix regex for file rm/ls

[talavis]

Escape the folder name before adding using it in a regex. Avoids missinterpretation of e.g. [].

Reverts #1019 since that change did nothing except making the query a bit uglier in the mariadb log.

Closes #1018

• Tests passing
• Black formatting
• [-] Migrations for any changes to the database schema
• Rebase/merge the dev branch
• Note in the CHANGELOG

[codecov]

Codecov Report

Merging #1029 (bd2fc37) into dev (3104aaa) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head bd2fc37 differs from pull request most recent head 418ad73. Consider uploading reports for the commit 418ad73 to get more accurate results

@@            Coverage Diff             @@
##              dev    #1029      +/-   ##
==========================================
+ Coverage   87.59%   87.61%   +0.01%     
==========================================
  Files          27       27              
  Lines        2943     2946       +3     
==========================================
+ Hits         2578     2581       +3     
  Misses        365      365              

Impacted Files	Coverage Δ
dds_web/api/files.py	83.98% <100.00%> (+0.15%)	⬆️

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[i-oden]

Tried uploading and downloading, deleting and listing. The commands that I've tested works with both special characters and without