feat: add vesting_base and vesting_investors NTRN-423 #22

[sotnikov-s]

task: https://p2pvalidator.atlassian.net/browse/NTRN-423

This PR:

• adds configuration via extensions (the managers, managed, query_at_height stuff) to the vesting_base;
• moves the whole vesting code to the vesting_base library and adds usage of vesting_base + configuration to the vesting-lp and vesting-managed;
• adds a new vesting-investors contract which combines query_at_height and managed features;
• adds tests for the vesting-investors contract which combines vesting-lp and vesting-managed contracts' tests.

Extensions explained:
Extensions usage is well described in the package's README.md file.

Invitation to love discussion:
I'd appreciate it if you guys could help me to come up with better names for extensions especially for the managed one. Currently it's Historical, WithManagers and Managed and the latter two are very much alike in names but quite different in meaning. I named the extension Managed after the eponymous vesting-managed contract, but I personally would like to rename both of them to something more meaningful. E.g. the vesting-managed contract is made for LTI, so maybe we could name it vesting-lti? Since we have a vesting-investors contract, that makes sense for me. The Managed extension could be named as Removable which also imo makes much more sense just by reading the name without getting deeper into the code. Renaming of the contract can be done in scope of another task.

Related PRs:

• add vesting extensions layer to exec msgs NTRN-423 neutron-integration-tests#134

Tests run: https://github.com/neutron-org/neutron-tests/actions/runs/4661122561