Adds a new option `fs.s3a.endpoint.fips` to switch the SDK client to use
FIPS endpoints, as an alternative to explicitly declaring them.
* The option is available as a path capability for probes.
* SDK v2 itself doesn't know that some regions don't have FIPS endpoints
* SDK only fails with endpoint + fips flag as a retried exception; wit this
change the S3A client should fail fast.
PR fails fast.
* Adds a new "connecting.md" doc; moves existing docs there and restructures.
* New Tests in ITestS3AEndpointRegion
bucket-info command support:
* added to list of path capabilities
* added -fips flag and test for explicit probe
* also now prints bucket region
* and removed some of the obsolete s3guard options
* updated docs
Contributed by Steve Loughran
d378853790