Make a new library.filter-path for the filter-graph that will filter and
restrict the dlopen filenames (used for the LADSPA plugin only).
By default this is false and so filter-chain can load from absolute
paths without extra checks.
Enable the extra checks for the pulse LADSPA modules and the
audioconvert filter graphs because these allow loading LADSPA plugins
into other processes.
Fixes#5222
61726f41d5