feat(svelte-query): add 'mutationOptions' (#10175)

* feat(svelte-query/mutationOptions): add 'mutationOptions' identity function for type-safe mutation configuration

* test(svelte-query/mutationOptions): add type and runtime tests for 'mutationOptions'

* docs(svelte-query/mutationOptions): add reference documentation for 'mutationOptions'

* chore(svelte-query): add changeset for 'mutationOptions'

* ci: apply automated fixes

* test(svelte-query/mutationOptions): use 'Accessor' type for props in BaseExample and wrap test values with arrow functions

* style(svelte-query/mutationOptions): remove blank lines between 'fireEvent' and assertion blocks

* refactor(svelte-query/mutationOptions): split BaseExample into BaseExample and MultiExample for single and multi mutation tests

* ci: apply automated fixes

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Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>