[ToggleButton] Remove deprecated APIs and add default utilities to variants

- Removes deprecated ToggleButton overloads and binary compatibility stubs in ToggleButtonDefaults.
- Adds utility functions and constants (size, MinHeight, IconSpacing, IconSize, contentPaddingFor, shape, pressedShape, checkedShape, shapesFor) to ElevatedToggleButtonDefaults, FilledTonalToggleButtonDefaults, and OutlinedToggleButtonDefaults for better discoverability.
- Adds size property to ToggleButtonDefaults and variant default objects as default for buttonSize in ToggleButton APIs.
- Updates KDocs to clarify that ToggleButtonSize configures internal layout defaults while layout modifiers (e.g., Modifier.size) can still adjust container dimensions.
- Replaces bullet lists in KDocs with @see tags and standard formatting.

Relnote: "Removed deprecated `ToggleButton` overloads. Added utility functions (`contentPaddingFor`, `shapesFor`) and default constants (including `size`) to `ToggleButtonDefaults`, `ElevatedToggleButtonDefaults`, `FilledTonalToggleButtonDefaults`, and `OutlinedToggleButtonDefaults`."
Test: ./gradlew :compose:material3:material3:connectedAndroidTest -Pandroid.testInstrumentationRunnerArguments.class=androidx.compose.material3.ToggleButtonTest
Bug: 516776680
Change-Id: I998cf18c0880f30a68e5be04faf9f65d5c192190