Improve the rounding off logic in Balance class (for changes in https://github.com/0chain/gosdk/pull/794)

[aniketsingh03]

A brief description of the changes in this PR:
This PR mirrors the changes needed in zbox for the changes made in 0chain/gosdk#794 which fixes 0chain/gosdk#752

Tasks to complete before merging PR:

• Ensure system tests are passing. If not Run them manually to check for any regressions 📋
• Do any new system tests need added to test this change? do any existing system tests need updated? If so create a PR at 0chain/system_test
• Merge your system tests PR to master AFTER merging this PR

Associated PRs (Link as appropriate):

• 0chain:
• blobber:
• gosdk: Improve the rounding off logic in Balance class gosdk#794
• system_test:
• zwalletcli: Changes conforming to https://github.com/0chain/gosdk/pull/794 zwalletcli#211
• Other: ...

[service-0chain]

Manual system tests [cancelled] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	NOT OVERRIDDEN
zboxcli	fix-rounding-off-for-balance
zwalletcli	staging
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	master
0proxy	staging
0search	staging

[service-0chain]

Manual system tests [failure] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	NOT OVERRIDDEN
zboxcli	fix-rounding-off-for-balance
zwalletcli	fix-rounding-off-for-balance
0chain	staging
blobber	staging
authorizer	staging
0box	fix-rounding-off-for-balance
0block	staging
0dns	staging
explorer	master
0proxy	staging
0search	staging

[service-0chain]

Manual system tests [cancelled] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	NOT OVERRIDDEN
zboxcli	fix-rounding-off-for-balance
zwalletcli	fix-rounding-off-for-balance
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	master
0proxy	staging
0search	staging

[dabasov]

lgtm

[service-0chain]

Manual system tests [failure] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	NOT OVERRIDDEN
zboxcli	fix-rounding-off-for-balance
zwalletcli	fix-rounding-off-for-balance
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	master
0proxy	staging
0search	staging

[service-0chain]

Manual system tests [failure] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	NOT OVERRIDDEN
zboxcli	fix-rounding-off-for-balance
zwalletcli	fix-rounding-off-for-balance
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	staging
0proxy	staging
0search	staging

[service-0chain]

Manual system tests [failure] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	fix-rounding-off-for-balance
zboxcli	fix-rounding-off-for-balance
zwalletcli	fix-rounding-off-for-balance
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	staging
0proxy	staging
0search	staging

[service-0chain]

Manual system tests [failure] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	NOT OVERRIDDEN
zboxcli	fix-rounding-off-for-balance
zwalletcli	staging
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	master
0proxy	staging
0search	staging

[peterlimg]

LGTM

[service-0chain]

Manual system tests [failure] with the following config

config	value
tests skipped	FALSE
system-tests	master
gosdk	staging
zboxcli	fix-rounding-off-for-balance
zwalletcli	fix-rounding-off-for-balance
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	staging
0proxy	staging
0search	staging

[service-0chain]

Manual system tests [success] with the following config

config	value
tests skipped	TRUE
system-tests	master
gosdk	staging
zboxcli	fix-rounding-off-for-balance
zwalletcli	staging
0chain	staging
blobber	staging
authorizer	staging
0box	staging
0block	staging
0dns	staging
explorer	staging
0proxy	staging
0search	staging