deprecate CONFIG_XOPEN_STREAMS in favour of CONFIG_XSI_STREAMS

[cfriedt]

Is your enhancement proposal related to a problem? Please describe.
CONFIG_XOPEN_STREAMS should be deprecated and renamed to CONFIG_XSI_STREAMS to be consistent with the pattern used for other XSI Option Groups.

See XSI Option Groups that are not listed in Suprofiling Considerations
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap02.html#tag_02_01_04_01

See XSI Option Groups at the bottom of this page
https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_subprofiles.html

Describe the solution you'd like

• the CONFIG_XOPEN_STREAMS Kconfig option should be deprecated
• a CONFIG_XSI_STREAMS Kconfig option should replace CONFIG_XOPEN_STREAMS
• documentation should be updated to reflect the change (with the exception that we need to preserve the _XOPEN_STREAMS POSIX Option)

Describe alternatives you've considered

Being inconsistent

Additional context

This ticket relates to #79816