Fix codesniffer errors in CloudflareVideoWidget

Problem/Motivation

FILE: ...temp/lwdalmnb/src/Plugin/Field/FieldWidget/CloudflareVideoWidget.php
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FOUND 2 ERRORS AND 3 WARNINGS AFFECTING 5 LINES
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5 | WARNING | [x] Unused use statement
6 | WARNING | [x] Unused use statement
10 | WARNING | [x] Unused use statement
51 | ERROR | [x] Expected 1 blank line after function; 0 found
52 | ERROR | [x] The closing brace for the class must have an empty
| | line before it