Improve range handling for price aggregation

[shochdoerfer]

Given I have a product with a price of 68.13 synced to Gally, the Gally response for the price aggregation filter will contain 68 as the maximum value. When sending the max value of 68 back to Gally, the product with the 68.13 price gets filtered out (since I am using a "lte" filter with 68).

My current "fix" in the Sylius connector is to add 1 to the max value sent by Gally. But I feel this is something that should not be the responsibility of the connector, but rather Gally should round up or add 1 to the max value.