feat(cmd): Add support for governance operations

[kostko]

Adds oasis network governance command with the following subcommands:

• list lists all governance proposals
• show moved from oasis network governance-proposal
• cast-vote votes for the proposal with yes/no/abstein
• create-proposal registers new proposal

[matevz]

Some refactoring suggestions.

[matevz]

Current example output for Testnet:

$ ./oasis acc gov show 7
Proposal passed, results: map[yes:50502292650718313]

Voted stake: 50502292650718313 (99.74%), total voting stake: 50632443796309264
Voted yes stake: 50502292650718313 (100.00%), voted stake: 50502292650718313, threshold: 68%

Validators voted:
oasis1qz2tg4hsatlxfaf8yut9gxgv8990ujaz4sldgmzx,<none>,10103361401282754 (19.95%)
oasis1qqv25adrld8jjquzxzg769689lgf9jxvwgjs8tha,<none>,10101056743564861 (19.95%)
oasis1qq2vzcvxn0js5unsch5me2xz4kr43vcasv0d5eq4,<none>,10099736164903599 (19.95%)
oasis1qz424yg28jqmgfq3xvly6ky64jqnmlylfc27d7cp,<none>,10099128300187338 (19.95%)
oasis1qr37y56g92chzvsew54kj7gu47cxyly7jytt5rm0,<none>,10099010040779761 (19.95%)

Validators not voted:
oasis1qrwncs459lauc77zw23efdn9dmfcp23cxv095l5z,GateOmega,36925612846659 (0.07%)
oasis1qq60zmsfca0gvmm3v8906pn5zqtt4ee2ssexramg,Validatrium,33743956828846 (0.07%)
oasis1qzjm0zwfg4egs9kk4d9rkujudzk8pjp5rvxyr3ag,Munay Network,11702422579124 (0.02%)
oasis1qpq97fm6lf87jzms9agd6z902nh7axtxvus6m352,LDV,10378819794784 (0.02%)
oasis1qpz97gfrvj5xzx8jx7x9zweeq0rcf2q6jg4a09qz,Stardust Staking,10086070309641 (0.02%)
oasis1qr2jxg57ch6p3787t2a8973v8zn8g82nxuex0773,Doorgod,9076788760953 (0.02%)
oasis1qz9x0zpja6n25hc5242k2e60l6a7ke2zsq9cqrqz,SerGo,5044216011403 (0.01%)
oasis1qqxxut9x74dutu587f9nj8787qz4dm0ueu05l88c,Princess Stake,2823252249537 (0.01%)
oasis1qq45am6gzaur2rxhk26av9qf7ryhgca6ecg28clu,Jr,2017758254984 (0.00%)
oasis1qzlzczsdme4scprjjh4h4vtljnmx3ag4vgpdnqln,Alexander (aka Bambarello) Validator,1593638024547 (0.00%)
oasis1qrq7hgvv26003hy89klcmy3mnedrmyd7lvf0k6qn,Perfect Stake,1403980986777 (0.00%)
oasis1qzwe6xywazp29tp20974wgxhdcpdf6yxfcn2jxvv,Simply Staking,1261098909212 (0.00%)
oasis1qphcvmsh6mw98vtg0cg4dvdsen5tm0g3e58eqpnp,Appload,1108526799775 (0.00%)
oasis1qpc66dgff4wrkj8kac4njrl2uvww3c9m5ycjwar2,<none>,1008643976345 (0.00%)
oasis1qpswaz4djukz0zanquyh2vswk59up22emysq5am9,StakeService,798000138962 (0.00%)
oasis1qr6a9jyxhvnxuq5kmtvntr0uv6mntvzvuyv57aqc,Orion.Money,480502898774 (0.00%)
oasis1qr4vsan850vmztuy9r2pex4fj4wxnmhvlgclg500,<none>,297535440854 (0.00%)
oasis1qqgvqelw8kmcd8k4cqypcsyajkl3gq6ppc4t34n2,AnkaStake,200251058019 (0.00%)
oasis1qzw6ljanmz8h4pjggemlgcysdnamaj830vlwu8c7,Mirror Frequency,200069721755 (0.00%)

I'm picky, but let's make printing more consistent with other commands:

• add Network: Testnet
• add Proposal ID: 7
• then something like Status: PASSED
• followed by Results:
• map[yes:50502292650718313] should be

     Yes: 50502292650718313
     No: 0
     Abstein: 0
  

• and then === VALIDATORS VOTED === with enumerated list of voters and the same for === VALIDATORS NOT VOTED ===

[matevz]

Moved governance cmd from account to network. New output:

$ oasis network governance show 7
Network:     localhost_testnet
Proposal ID: 7
Status:      passed
Results:
  - yes: 50502292650718313
  - no: 0
  - abstain: 0

=== VOTED STAKE ===
Total voting stake: 50632443796309264
Voted stake:        50502292650718313 (99.74%)
Voted yes stake:    50502292650718313 (100.00%)
Threshold:          68%

=== VALIDATORS VOTED ===
  1. oasis1qz2tg4hsatlxfaf8yut9gxgv8990ujaz4sldgmzx,<none>,10103361401282754 (19.95%)
  2. oasis1qqv25adrld8jjquzxzg769689lgf9jxvwgjs8tha,<none>,10101056743564861 (19.95%)
  3. oasis1qq2vzcvxn0js5unsch5me2xz4kr43vcasv0d5eq4,<none>,10099736164903599 (19.95%)
  4. oasis1qz424yg28jqmgfq3xvly6ky64jqnmlylfc27d7cp,<none>,10099128300187338 (19.95%)
  5. oasis1qr37y56g92chzvsew54kj7gu47cxyly7jytt5rm0,<none>,10099010040779761 (19.95%)

=== VALIDATORS NOT VOTED ===
  1. oasis1qrwncs459lauc77zw23efdn9dmfcp23cxv095l5z,GateOmega,36925612846659 (0.07%)
  2. oasis1qq60zmsfca0gvmm3v8906pn5zqtt4ee2ssexramg,Validatrium,33743956828846 (0.07%)
  3. oasis1qzjm0zwfg4egs9kk4d9rkujudzk8pjp5rvxyr3ag,Munay Network,11702422579124 (0.02%)
  4. oasis1qpq97fm6lf87jzms9agd6z902nh7axtxvus6m352,LDV,10378819794784 (0.02%)
  5. oasis1qpz97gfrvj5xzx8jx7x9zweeq0rcf2q6jg4a09qz,Stardust Staking,10086070309641 (0.02%)
  6. oasis1qr2jxg57ch6p3787t2a8973v8zn8g82nxuex0773,Doorgod,9076788760953 (0.02%)
  7. oasis1qz9x0zpja6n25hc5242k2e60l6a7ke2zsq9cqrqz,SerGo,5044216011403 (0.01%)
  8. oasis1qqxxut9x74dutu587f9nj8787qz4dm0ueu05l88c,Princess Stake,2823252249537 (0.01%)
  9. oasis1qq45am6gzaur2rxhk26av9qf7ryhgca6ecg28clu,Jr,2017758254984 (0.00%)
  10. oasis1qzlzczsdme4scprjjh4h4vtljnmx3ag4vgpdnqln,Alexander (aka Bambarello) Validator,1593638024547 (0.00%)
  11. oasis1qrq7hgvv26003hy89klcmy3mnedrmyd7lvf0k6qn,Perfect Stake,1403980986777 (0.00%)
  12. oasis1qzwe6xywazp29tp20974wgxhdcpdf6yxfcn2jxvv,Simply Staking,1261098909212 (0.00%)
  13. oasis1qphcvmsh6mw98vtg0cg4dvdsen5tm0g3e58eqpnp,Appload,1108526799775 (0.00%)
  14. oasis1qpc66dgff4wrkj8kac4njrl2uvww3c9m5ycjwar2,<none>,1008643976345 (0.00%)
  15. oasis1qpswaz4djukz0zanquyh2vswk59up22emysq5am9,StakeService,798000138962 (0.00%)
  16. oasis1qr6a9jyxhvnxuq5kmtvntr0uv6mntvzvuyv57aqc,Orion.Money,480502898774 (0.00%)
  17. oasis1qr4vsan850vmztuy9r2pex4fj4wxnmhvlgclg500,<none>,297535440854 (0.00%)
  18. oasis1qqgvqelw8kmcd8k4cqypcsyajkl3gq6ppc4t34n2,AnkaStake,200251058019 (0.00%)
  19. oasis1qzw6ljanmz8h4pjggemlgcysdnamaj830vlwu8c7,Mirror Frequency,200069721755 (0.00%)

[matevz]

LGTM