logger: Add unique verbose prefixes for levels 5-10.

[InterLinked1]

Add unique verbose prefixes for levels higher than 4, so that these can be visually differentiated from each other.

Resolves: #721

[github-actions[bot]]

REMINDER: If this PR applies to other branches, please add a comment with the appropriate "cherry-pick-to" headers as per the Create a Pull Request process.

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The currently active branches are now 18, 20, 21 and master.

[InterLinked1]

cherry-pick-to: 18 cherry-pick-to: 20 cherry-pick-to: 21

[github-actions[bot]]

Successfully merged to branch master and cherry-picked to ["18","20","21"]