feat: implement txs generate and txs clear command

[harry-hov]

Adds generate and clear to gnoland genesis txs command

generate  generates addpkg txs from dir and add them to genesis.json
clear     clears all the transactions from the genesis.json

With these changes, initial set of packages can be added to genesis.json using gnoland genesis txs generate /examples. Next step is to remove genesis generation logic from gnoland start; so that gnoland start can only focus on starting the node properly.

Related: #1952

[codecov]

Codecov Report

Attention: Patch coverage is 76.25000% with 19 lines in your changes are missing coverage. Please review.

Project coverage is 48.40%. Comparing base (edb321f) to head (9d788e8).

Files	Patch %	Lines
gno.land/pkg/gnoland/genesis.go	0.00%	7 Missing ⚠️
gno.land/cmd/gnoland/genesis_txs_add.go	58.33%	2 Missing and 3 partials ⚠️
gno.land/cmd/gnoland/genesis_txs_generate.go	86.20%	2 Missing and 2 partials ⚠️
gno.land/cmd/gnoland/genesis_txs_clear.go	92.85%	1 Missing and 1 partial ⚠️
gno.land/pkg/integration/testing_node.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1988      +/-   ##
==========================================
- Coverage   54.64%   48.40%   -6.25%     
==========================================
  Files         578      411     -167     
  Lines       77870    62408   -15462     
==========================================
- Hits        42551    30207   -12344     
+ Misses      32149    29684    -2465     
+ Partials     3170     2517     -653     

Flag	Coverage Δ
contribs/gnodev	?
contribs/gnofaucet	?
contribs/gnokeykc	?
contribs/gnomd	?
gno.land	61.97% <76.25%> (+0.33%)	⬆️
gnovm	?
misc/autocounterd	?
misc/genproto	?
misc/genstd	?
misc/goscan	?
misc/logos	?
misc/loop	?
tm2	?

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[zivkovicmilos]

I think this PR is overcomplicating already existing functionality (genesis txs). The subcommands are practically copy pasted from the mentioned command suite.

• add - what do we accomplish with this, that we don't already with genesis txs add?
• clear - this would've been a good addition to genesis txs
• list - this would've been a good addition to genesis txs
• get - I'm not sure when anybody would use this
• del - what do we accomplish with this, that we don't already with genesis txs remove?

What I'm trying to say is -- we already had this functionality in some form or another, so there is no need to define an entirely new command suite for it (that we have to maintain). Please consider refactoring this PR to improve the existing genesis txs command suite with additional / more richer functionality 🙏

[harry-hov]

@zivkovicmilos I have applied the changes as requested

Added these subcommands to genesis txs:

generate  generates addpkg txs from dir and add them to genesis.json
clear     clears all the transactions from the genesis.json

[zivkovicmilos]

Closing in favor of #2327