Fixes during update contract parameters process

[greenhat]

Close #160
Close #162
Close #163
Close #165
Close #166
Close #167
Close #168
Close #170

[coveralls]

Pull Request Test Coverage Report for Build 3531539433

• 4 of 41 (9.76%) changed or added relevant lines in 6 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.7%) to 64.698%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
core/src/actions.rs	0	1	0.0%
core/src/cli_commands/update_pool.rs	1	2	50.0%
core/src/cli_commands/vote_update_pool.rs	1	2	50.0%
core/src/main.rs	0	1	0.0%
core/src/serde.rs	0	2	0.0%
core/src/cli_commands/prepare_update.rs	2	33	6.06%

Files with Coverage Reduction	New Missed Lines	%
core/src/cli_commands/prepare_update.rs	1	73.4%

Totals
Change from base Build 3515361119:	-0.7%
Covered Lines:	1961
Relevant Lines:	3031

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💛 - Coveralls