[HttpKernel] added logging when an inline fragment cannot be rendered and ignore_errors is on
merged branch fabpot/inline-fragment-logging (PR #7799)

This PR was merged into the master branch.

Discussion
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[HttpKernel] added logging when an inline fragment cannot be rendered and ignore_errors is on

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7339, #1991, #6400
| License       | MIT
| Doc PR        | n/a

This is a rebased and tested version of #7339. This is probably not the most beautiful code, but it gets the job done and does the exact same thing as any other exception handling.

Commits
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7ef73b1 [HttpKernel] added logging when an inline fragment cannot be rendered and ignore_errors is on