[TASK] Remove css_styled_content legacy templates before 4.5

This change simply removes legacy files - no other changes.

Resolves: #54621
Releases: 6.2
Change-Id: Ief7287eee5a2f6ccfecdb274ae7c54a04f1a2247
Reviewed-on: https://review.typo3.org/26573
Reviewed-by: Nikolas Hagelstein
Reviewed-by: Helmut Hummel
Reviewed-by: Marcin S?gol
Tested-by: Marcin S?gol
Reviewed-by: Tom Ruether
Tested-by: Tom Ruether
Reviewed-by: Felix Kopp
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter