n-api: run all finalizers via SetImmediate()

Throwing an exception from a finalizer can cause the following fatal
error:

Error: async hook stack has become corrupted (actual: 2, expected: 0)
 1: 0x970b5a node::InternalCallbackScope::~InternalCallbackScope()
    [./node]
 2: 0x99dda0 node::Environment::RunTimers(uv_timer_s*) [./node]
 3: 0x13d8b22  [./node]
 4: 0x13dbe42 uv_run [./node]
 5: 0xa57974 node::NodeMainInstance::Run() [./node]
 6: 0x9dbc17 node::Start(int, char**) [./node]
 7: 0x7f4965417f43 __libc_start_main [/lib64/libc.so.6]
 8: 0x96f4ae _start [./node]

By https://github.com/nodejs/node/issues/34341#issuecomment-658426281

,
calling into JS from a finalizer and/or throwing exceptions from there
is not advised, because the stack may or may not be set up for JS
execution. The best solution is to run the user's finalizer from a
`SetImmediate()` callback.

Signed-off-by: Gabriel Schulhof <gabriel.schulhof@intel.com>
Fixes: https://github.com/nodejs/node/issues/34341
PR-URL: https://github.com/nodejs/node/pull/34386


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>