Add missing actionability options: `position_x`/`position_y`/`trial` on `Check Checkbox`/`Uncheck Checkbox`, `force` on `Clear Text` and `Select Options By`

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## Use case

Several element-interaction keywords expose fewer of Playwright's actionability options than their siblings, which surprises users and forces JavaScript workarounds:

- **Custom-styled checkboxes** often hide the real `` under a styled overlay. `Click With Options` and `Tap` let users click a specific point of the element (`position_x`/`position_y`) or dry-run the actionability checks (`trial`), but `Check Checkbox`/`Uncheck Checkbox` only accept `force`. When the input's center is covered but an edge is clickable, users today must give up on the semantic checkbox keywords and fall back to `Click With Options` — losing the built-in checked-state handling.
- **`Clear Text` and `Select Options By` have no `force` argument at all**, although nearly every other interaction keyword (`Click`, `Check Checkbox`, `Hover`, `Tap`, …) has one. When a field or select is technically actionable but Playwright's checks disagree (transient overlays, exotic widgets), there is currently no escape hatch for these two keywords.

This is a consistency gap: the options exist in Playwright for all of these actions; the library simply does not forward them.

## Proposed keyword / arguments

All new arguments are named-only with behavior-preserving defaults.

`Check Checkbox` and `Uncheck Checkbox` gain (matching the existing `Tap` signature):

- `position_x: int | None = None`, `position_y: int | None = None` — point to click relative to the element's top-left corner.
- `trial: bool = False` — perform only the actionability checks, skip the actual action.

`Clear Text` and `Select Options By` gain:

- `force: bool = False` — bypass the actionability checks.

```robotframework
# Styled checkbox whose real input is covered except at its top-left corner
Check Checkbo    id=terms position_x=2 position_y=2
Uncheck Checkbox id=terms position_x=2 position_y=2

# Only verify the checkbox is actionable, without changing its state
Check Checkbox id=terms trial=True

Clear Text id=search-input force=True
Select Options By select[name=channel] label Direct mail force=True
Get Checkbox State id=terms == checked
```

## Playwright API

- [`locator.check`](https://playwright.dev/docs/api/class-locator#locator-check) / [`locator.uncheck`](https://playwright.dev/docs/api/class-locator#locator-uncheck) — options `position` and `trial`.
- [`locator.clear`](https://playwright.dev/docs/api/class-locator#locator-clear) — option `force`.
- [`locator.selectOption`](https://playwright.dev/docs/api/class-locator#locator-select-option) — option `force`.

## Implementation notes

- `protobuf/playwright.proto`: the checkbox RPCs currently use `ElementSelector` with a `force` flag; they need either an options-JSON request (like `Click`'s `ElementSelectorWithOptions`) or added fields. `Clear Text` / `SelectOption` requests need a `force` flag.
- `node/playwright-wrapper` interaction handlers: forward `position`, `trial`, `force` to the corresponding locator calls.
- `Browser/keywords/interaction.py`: extend `check_checkbox`, `uncheck_checkbox`, `clear_text`, `select_options_by` signatures (named-only). Note `select_options_by` uses `*values`, so `force` must be keyword-only after it.
- Docs and atest cases (a covered-checkbox fixture may need to be added to the test app).

## Backwards compatibility

All arguments are new and named-only with defaults (`None`/`False`) that reproduce the current behavior exactly; no existing suite is affected.

Start with the checkbox and interaction requests in protobuf/playwright.proto, then trace their handlers in node/playwright-wrapper and the keyword signatures in Browser/keywords/interaction.py. Review the existing Click options, atest cases, and documentation patterns before adding the named-only options. Done means all four keywords forward the requested options while preserving defaults, with coverage for checkbox positioning/trial and force behavior.

Written by the indexing model from the issue text.