Fixes in bulk staging function

[hailihu]

Fixes to bulk staging:

• Stage file-list as array in a single bulk request
• Put target in requests.log
• Add activity (PIN ur UNPIN) of bulk request in requests.log
• Except for storing the request ID in ~/.ada/requests.log, return the request ID to the prompt when a stage/unstage command is submitted.
• In debug mode, mention that information about bulk request is logged in requests.log
• Remove default lifetime from unstage/unpin command

[hailihu]

ADA commands tested are:

# stage file
./ada --tokenfile tokenfile_prod.conf --stage ${prod_tape_path}/${filename} --lifetime 1D --api "${prod_api_url}" --debug

# stage dir recursively
./ada --tokenfile tokenfile_prod.conf --stage ${prod_tape_path}/${dirname} --lifetime 1D --api "${prod_api_url}" --debug --recursive

# stage from file
./ada --tokenfile tokenfile_prod.conf --stage --from-file file-list --lifetime 1D --api "${prod_api_url}" --debug

# unstage file
./ada --tokenfile tokenfile_prod.conf --unstage ${prod_tape_path}/${filename} --api "${prod_api_url}" --debug

# unstage dir
./ada --tokenfile tokenfile_prod.conf --unstage ${prod_tape_path}/${dirname} --api "${prod_api_url}" --debug --recursive

# unstage from file
./ada --tokenfile tokenfile_prod.conf --unstage --from-file file-list --api "${prod_api_url}"  --debug