fix: respect lifecycle.ignore_changes in settings resource

[JEETDESAI25]

What kind of change does this PR introduce?

Bug fix for supabase_settings respecting lifecycle.ignore_changes.

What is the current behavior?

Closes #229. Even when lifecycle.ignore_changes includes auth (or other settings blocks), the provider still calls the update APIs. During imports the plan carries the existing JSON, so Update() sees non-null values and always invokes updateAuthConfig/updateNetworkConfig/etc., leading to unnecessary API errors.

What is the new behavior?

• Update() now reads both plan and state and only calls updateDatabase/Network/Api/Auth when the jsontypes.Normalized values differ (semantic JSON comparison).
• Adds TestAccSettingsResource_IgnoreChanges: applies a settings resource, updates only the network with lifecycle.ignore_changes = [auth], and asserts the auth PATCH endpoint is never hit.

Additional context

• Verified locally with TF_ACC=1 go test -v ./internal/provider/ -timeout 5m and targeted runs for all settings tests.
• golangci-lint run ./internal/provider/... passes with 0 issues.
• The comparison logic applies identically to all JSON settings blocks (database, network, api, auth). Regression test specifically validates auth being ignored and network being updated.