Create a router to add liquidity with underlying to an initialized buffer

[joaobrunoah]

ZenDragon mentioned that it's hard to add liquidity to an already initialized buffer, since you can be frontrun when posting the add liquidity transaction and it's hard to tell how much underlying and wrapped token to have. A solution would be to create a router function that makes it easier to add liquidity using only the underlying.

This router should receive underlying amount and wrapped token as argument, and follow the step-by-step:

• Get the buffer balance;
• get the wrapped token rate;
• Calculate the amount of tokens to wrap, so that the add liquidity is proportional
• Wrap tokens using the wrapped token directly
• Add liquidity to the buffer proportionally
• Return "leftovers" to the sender