[BUGFIX] New content elements are always stored on pid 0

Due to patch https://review.typo3.org/#/c/30305/ the string comparison
on colPos fails and new content elements are always stored on pid 0.
This patch corrects the check for an integer colPos type by setting the
unused variable to NULL.

Resolves: #59059
Releases: 6.2, 6.1, 6.0, 4.7, 4.5
Change-Id: Iecd7f0cacf5c9315d882eebeb3893bcfa63ae7eb
Reviewed-on: https://review.typo3.org/30419
Tested-by: SITS Developer
Reviewed-by: Markus Klein
Tested-by: Markus Klein
[BUGFIX] AbstractBackendViewHelper uses namespaces

Namespaces are not supported in PHP 5.2.x, hence one must not
prefix a class name with backslash.

Regression fix to #54748.

Resolves: #59825
Releases: 4.5
Change-Id: Ideb2cef1c5e2ec0d2ac3328ebd4f318a161d368a
Reviewed-on: https://review.typo3.org/31084
Tested-by: Sebastian Sommer
Tested-by: Steffen Mächtel
Reviewed-by: Markus Klein
Tested-by: Markus Klein