Fix spelling

[umlaeute]

• Related: spellingerrors obs-studio#11160

Description

Fixes a number of spelling mistakes in log-messages, documentation and comments.

Motivation and Context

Proper English makes log-messages, documentation and code more readable.

How Has This Been Tested?

still builds

Types of changes

• Code cleanup (non-breaking change which makes code smaller or more readable)

• Documentation (a change to documentation pages)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.