FINERACT-2770: Tax - Unable to edit a tax group

[rymghosn]

TaxGroupComponent (the request DTO used by POST /v1/taxes/group and
PUT /v1/taxes/group/{taxGroupId}) was missing the id and endDate
fields — it only declared taxComponentId and startDate.
TaxGroupApiResource#createTaxGroup/#updateTaxGroup deserialize the
incoming JSON request body into this DTO and then re-serialize it before
handing it off to the command handler. Because the DTO didn't declare
id/endDate, Jackson silently dropped those values during that
round-trip for any client that submitted them — before the tax group's
write-platform service or validators ever saw them. In practice this made
it impossible to correctly update an existing tax group's components (e.g.
resubmitting an existing component's id, or setting/keeping its
endDate).
This is a pre-existing mismatch between the DTO and its own documented
contract: TaxGroupApiResource's Swagger docs already state

Optional Fields in taxComponents: id, startDate and endDate

for tax group creation — the DTO just never actually had the id/endDate
fields to back that documentation.

Fix

Add the missing id and endDate fields to TaxGroupComponent, matching
what the API already documents and what TaxGroupData/response-side
mapping already expects.
PR:(https://issues.apache.org/jira/browse/FINERACT-2770)