Introduce 'submodule.recurse' option for worktree manipulators

Introduce 'submodule.recurse' option for worktree manipulators

Any command that understands '--recurse-submodules' can have its
default changed to true, by setting the new 'submodule.recurse'
option.

This patch includes read-tree/checkout/reset for working tree
manipulating commands. Later patches will cover other commands.

Signed-off-by: Stefan Beller <redacted>
Signed-off-by: Junio C Hamano <redacted>