refactor net-level alarm handling

[astrophysik]

Changes

Refactor system level alarm handling

Before this pr alarm and wakeup have been processed by same *_php_wakeup functions. This pr add *_php_alarm functions for processing situations when c->flags == C_ALARM Also were added different entry points in PhpWorker lifecycle to execute special logic on alarm

Enable shutdown functions on timeouts in net context

This pr enable shutdown functions for timeouts in net context and add some tests for this cases

Fix sleep functions with timeout

Before this pr f$usleep(...) disable left timeout if it was less then sleeping time and ignore it in future