sdbus++: events: adjust schema for metadata

Switch the preferred format of metadata from SNAKE_CASE to CamelCase.
This has no affect on the metadata names in the phosphor-logging
object as those will still be generated as SNAKE_CASE.

SNAKE_CASE is a lossy format.  Consider `BMC_ADDRESS`; it cannot be
identified if BMC is an acronym or a word.  Our conversion functions
will convert this to `bmcaddress` when becoming a camelCase format
since there is special handling for acronyms and this will appear
equivalent to an acronym.

All of the generators for events are explicit to use `foo.camelCase` or
`foo.SNAKE_CASE` as appropriate, so switching to CamelCase has little
effect.  The primary thing it does is make the event class member
variables named sanely: `numberOfLogs` rather than `numberoflogs`.

This will require a minor edit to the few events that are defined
in phosphor-dbus-interfaces already, which will be done at the same
time.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I10310986b9214aec99a3c7eabecf55f7054cdad0
diff --git a/tools/sdbusplus/schemas/events.schema.yaml b/tools/sdbusplus/schemas/events.schema.yaml
index 1ee280b..fe7f499 100644
--- a/tools/sdbusplus/schemas/events.schema.yaml
+++ b/tools/sdbusplus/schemas/events.schema.yaml
@@ -27,8 +27,9 @@
                     properties:
                         name:
                             type: string
-                            pattern: "^[A-Z_][A-Z0-9_]*$"
-                            description: The name of the metadata field.
+                            pattern: "^[A-Z][A-Z0-9a-z]*$"
+                            description:
+                                The name of the metadata field in CamelCase.
                         description:
                             type: string
                             description: