[BUGFIX] Extension manager styling

The extension manager never got all defined styles.
Bring several visual improvements:

— placeholder in search field
— show action icons on hover
— style extension state column
— float table header cols left and right

Change-Id: Id6eafa2b28b1d054929a84400bf1648b6e1e6d75
Fixes: #45928
Releases: 6.0, 6.1
Reviewed-on: https://review.typo3.org/18544
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
Reviewed-by: Jost Baron
Tested-by: Jost Baron
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
[BUGFIX] Caching framework tables depends on ext_tables.sql

Since TYPO3 version 4.6 the caching framework should be responsible to
create needed tables for itself. But this is only executed when the
extension contains ext_tables.sql file in its extension folder. If you do
not need any other tables/fields no caching framework tables are created.
This should be independent from ext_tables.sql

Change-Id: Ifba3cb7bcc94d09627b38d5b5962cfdb2282306b
Fixes: #46591
Releases: 6.1, 6.0
Reviewed-on: https://review.typo3.org/19214
Reviewed-by: Sascha Egerer
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn