soroban-cli: add fees command line parameter

[tsachiherman]

What ?

Add fees command line argument. Currently, we have the following comment in the source code:

 // TODO: create a cmdline parameter for the fee instead of simply using the minimum fee

Where ?

The soroban-cli has the above comment in 4 locations:

• deploy.rs
• install.rs
• invoke.rs
• wrap.rs

For all of these, we want to use the existing value ( 100 ), as the default value, while allowing the end user to override these with a different value.