Relaxing IsConnected Check for Datagram Sockets

[liveans]

Fixes #77962

.NET Framework's behavior may be different for SocketType.Stream, but this PR will match the behavior for other socket types.

According to linux connect man page

Some protocol sockets (e.g., datagram sockets in the UNIX and
Internet domains) may use connect() multiple times to change
their association.

According to WinSock2 connect api

For a connectionless socket:
The default destination can be changed by simply calling connect again, even if the socket is already connected.

According to OSX connect man page:

Each communications space interprets the address parameter in its own
way.  Generally, stream sockets may successfully connect() only once;
datagram sockets may use connect() multiple times to change their association. 
Datagram sockets may dissolve the association by connecting to an
invalid address, such as a null address or an address with the address
family set to AF_UNSPEC (the error EAFNOSUPPORT will be harmlessly
returned).

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Issue Details

---

Fixes #77962

Author:	liveans
Assignees:	-
Labels:	area-System.Net.Sockets
Milestone:	-

[stephentoub]

Looks like this was introduced as part of another bug fix in dotnet/corefx#27173

[liveans]

/azp run runtime-libraries-coreclr outerloop

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