Aliases in credential stores should be case insensitive

Working with credential store aliases should be case insensitive.

Current behavior, when aliases are converted to lowercase during add operation is not user-friendly. Subsequent operations should also support automatic conversion to lowercase.

E.g.

/subsystem=elytron/credential-store=cred-store-default/alias=UPPER:add(secret-value=password)
/subsystem=elytron/credential-store=cred-store-default/alias=UPPER:remove()

Current behavior:
First command succeeds and the second fails as the alias is changed to "upper" (in lowercase).

Expected behavior:
Both commans succeeds.

Unignore tests
When this issue is fixed, unignore (and fix if needed) related tests in testsuite/elytron/src/test/java/org/wildfly/test/integration/elytron/application/. Thanks.

git grep WFLY-8131