Add depositAndPause function

[andreivladbrg]

Ref #58 and #92 (comment)

Depends on

• Change cancel over pause function #85

[andreivladbrg]

for the simplicity of this function, the implementation can call deposit and then pause:

function depositAndPause(uint256 streamId) external {
     uint128  debt = streamDebtOf(streamId);
     deposit(streamId, debt);
     pause(streamId);
}