Minimize the constructor functions to a bare minimum.

Most of the constructors are supposed to be only a call of

  new TheInstance(arguments)

or an equivalent; so let's just change the constructor caller accordingly, to
accept unacquired new instance.

If there are exceptions that need to do more heavy lifting, they do not have
to use the constructor feature, or there can be a wrapper for the real
implementation, doing the additional work in their (C++) constructor.

Change-Id: I035c378778aeda60d15af4e56ca3761c586d5ded
Revert "svt: Use constructor feature for FilePicker and FolderPicker..."

It does not make a real sense to use constructor for implementations that act
as a trampoline; instead, we should do a constructor for the real
implementations that hide behind it.

This reverts commit 2fbb47156773b2e300fc987efc2da85c66e567d1.
This reverts (part of) commit 58ea27124af27bfac21a796b0d13d72354bd0dd3.
This reverts (part of) commit 194bdbde25dd70988c94ff5e1af43b530d47d94b.
This reverts (part of) commit df002e39f7518036ae1c1d2afec7a525ef902327.
This reverts (part of) commit eb89c6f7dcd613cda6a9eee6f7897225e0334a25.
This reverts (part of) commit bdeb57c23973f3ef79020847b2fe39f312cf3c0b.
This reverts (part of) commit 4337a0664f4fb73f9e1be74f2a632847871da402.

Change-Id: Ibd9b1066f3b6ea215d8da9f491d5f026cd75b029