rofl-client/ts: Support u128 as tx.value

[rube-de]

Current ts rofl-client uses js number and limiting it to u53.

[njelich]

Should support for js numbers simply be removed then? BigInts and Strings are supported.

function normalizeEthValue(value: EthValue): string {
    if (typeof value === 'bigint') {
        if (value < 0n) {
            throw new Error('EthTx.value cannot be negative');
        }
        return value.toString(10);
    }
    if (typeof value === 'number') {
        if (!Number.isFinite(value) || !Number.isSafeInteger(value) || value < 0) {
            throw new Error('EthTx.value numbers must be safe non-negative integers');
        }
        return BigInt(value).toString(10);
    }
    if (typeof value === 'string') {
        const trimmed = value.trim();
        if (!trimmed) {
            throw new Error('EthTx.value string must not be empty');
        }
        let parsed: bigint;
        try {
            parsed = BigInt(trimmed);
        } catch {
            throw new Error(
                'EthTx.value string must be a decimal integer or 0x-prefixed hex literal',
            );
        }
        if (parsed < 0n) {
            throw new Error('EthTx.value cannot be negative');
        }
        return parsed.toString(10);
    }
    throw new Error('EthTx.value must be a string, number, or bigint');
}