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• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce?
Feature.

What is the current behavior?
Form elements that rendered multiple options, such as Select, CheckboxGroup, RadioGroup, CheckboxButtons and RadioButtons did not use the same API. The rendering mechanism was individual to each of them as well, not providing an optimal DX.

What is the new behavior?
Form elements that render multiple options, such as Select, CheckboxGroup, RadioGroup, CheckboxButtons and RadioButtons now use an options prop, where each option uses the following format:

export interface FormOption {
    id: string | number;
    label?: Renderable;
    value?: FormValue;
    disabled?: boolean;
    readonly?: boolean;
    [key: string]: any;
}

The id is required and will be always used to set the modelValue of the form element. The options array usage would look as follows:

<script lang="ts" setup>
    const selected = ref('apple');
    const options = ref<FormOption[]>([
        { id: 'apple', label: 'Apple' },
        { id: 'banana', label: 'Banana' },
        { id: 'strawberry', label: 'Strawberry' }
    ]);
</script>
<template>
    <IRadioGroup v-model="selected" :options="options" />
</template>

Each of the above mentioned components now also has a label prop that is used as fallback if the option item does not provide a label field. The component label prop and option label field introduce a new concept called Renderable to Inkline. Which can be one of the following:

• a string i.e. Label
• an expression that can reference any field of the options array item i.e. {{address.country}}
• a render function returning a string i.e. (option: FormOption) => Hello ${option.id}`
• a render function returning a hoisted element i.e. (option: FormOption) => h('strong', {}, option.id)
• a Vue component (needs to be marked as raw to disable reactivity) i.e. markRaw(MyComponent)

Does this PR introduce a breaking change?
The ISelect, ICheckboxGroup and IRadioGroup will need to be updated to use the format above.