[FEATURE] Improve the info popup

The change improves the general spacing and CGL of the code,
removes some unused variables, tailores some very long lines
for better readability, adds the creation date, creation user
and last modified timestamp of the record and adds some general
actions to the references which improve the usability of the
feature a lot.

Change-Id: Iad2ec3ca01707a1486e2785115e3c5c25f6e1c57
Resolves: #38469
Releases: 6.0
Reviewed-on: http://review.typo3.org/12420
Reviewed-by: Susanne Moog
Tested-by: Susanne Moog
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn

typo3/sysext/lang/locallang_general.xlf

@@ -9,6 +9,15 @@
 			<trans-unit id="LGL.hidden" xml:space="preserve">
 				<source>Hide:</source>
 			</trans-unit>
+			<trans-unit id="LGL.timestamp" xml:space="preserve">
+				<source>Last Modified:</source>
+			</trans-unit>
+			<trans-unit id="LGL.creationDate" xml:space="preserve">
+				<source>Created At:</source>
+			</trans-unit>
+			<trans-unit id="LGL.creationUserId" xml:space="preserve">
+				<source>Created By:</source>
+			</trans-unit>
 			<trans-unit id="LGL.starttime" xml:space="preserve">
 				<source>Start:</source>
 			</trans-unit>