Add monitor based sync only locker for ReadWrite cache

[bahusoid]

Fixes #2862

Adds ability to use old lock based locking for sync only scenarios. Reason: As described here in full .NET Framework current locking code is 300 times slower.

Throws InvalidOperationException when used in async code.

Usage:

<session-factory>
  <property name="cache.read_write_lock_factory">sync</property>
</session-factory>

Or by code:

Configuration cfg = ...;
cfg.SetProperty(Environment.CacheReadWriteLockFactory, "sync");

It's also possible to provide custom locker. See #2862 (comment)

[fredericDelaporte]

May you also insert a documentation entry in the below file after the query cache factory setting?

nhibernate-core/doc/reference/modules/configuration.xml

Lines 600 to 612 in 92075ee

	<row>
	<entry>
	<literal>cache.query_cache_factory</literal>
	</entry>
	<entry>
	The class name of a custom <literal>IQueryCacheFactory</literal> implementation.
	Defaults to the built-in <literal>StandardQueryCacheFactory</literal>.
	<para>
	<emphasis role="strong">eg.</emphasis>
	<literal>classname.of.QueryCacheFactory, assembly</literal>
	</para>
	</entry>
	</row>

                    <row>
                        <entry>
                            <literal>cache.read_write_lock_factory</literal>
                        </entry>
                        <entry>
                            Specify the cache lock factory to use for read-write cache regions.
                            Defaults to the built-in <literal>async</literal> cache lock factory.
                            <para>
                                <emphasis role="strong">eg.</emphasis>
                                <literal>async</literal>, or <literal>sync</literal>, or <literal>classname.of.CacheLockFactory, assembly</literal>
                            </para>
                            <para>
                                <literal>async</literal> uses a single writer multiple readers locking mechanism supporting asynchronous operations.
                            </para>
                            <para>
                                <literal>sync</literal> uses a single access locking mechanism which will throw on asynchronous
                                operations but may have better performances than the <literal>async</literal> provider for applications using
                                the .Net Framework (4.8 and below).
                            </para>
                        </entry>
                    </row>

[bahusoid]

May you also insert a documentation entry

Done