Add RocksDB create checkpoint interface - Closes #54

[matjazv]

What was the problem?

This PR resolves #54

How was it solved?

Function for creating RocksDB checkpoint for Database and StateDB is exposed to JS library and it is possible to call it from JS code.

How was it tested?

• some new tests were implemented
• all tests passed

[github-actions]

Commit SHA:a2048e6d5604c6ae7e141829f92e58921cb2f017

Test coverage results 🧪

Code coverage diff between base branch:main and head branch: 54_checkpoint_interface 

Status	File	% Stmts	% Branch	% Funcs	% Lines
🟢	total	74.11 (0.78)	59.06 (1.13)	78.72 (0.95)	73.96 (0.79)
🟢	database.js	76.03 (1.03)	57.14 (1.83)	80 (0.97)	76.03 (1.03)
🟢	state_db.js	68.9 (0.98)	57.31 (1.06)	70.68 (1.59)	68.9 (0.98)

[shuse2]

Generally Looks good to me.
Please also update types.d.ts for Database and StateDB to include

checkpoint(path: string): Promise<void>;

[github-actions]

Commit SHA:756d188dabeb3ff72ab24a580e7bca6629867a8e

Test coverage results 🧪

Code coverage diff between base branch:main and head branch: 54_checkpoint_interface 

Status	File	% Stmts	% Branch	% Funcs	% Lines
🟢	total	74.11 (0.78)	59.06 (1.13)	78.72 (0.95)	73.96 (0.79)
🟢	database.js	76.03 (1.03)	57.14 (1.83)	80 (0.97)	76.03 (1.03)
🟢	state_db.js	68.9 (0.98)	57.31 (1.06)	70.68 (1.59)	68.9 (0.98)

[github-actions]

Commit SHA:e8b10076d12626733c29a2abef13edac8eca3c48

Test coverage results 🧪

Code coverage diff between base branch:main and head branch: 54_checkpoint_interface 

Status	File	% Stmts	% Branch	% Funcs	% Lines
🟢	total	74.11 (0.78)	59.06 (1.13)	78.72 (0.95)	73.96 (0.79)
🟢	database.js	76.03 (1.03)	57.14 (1.83)	80 (0.97)	76.03 (1.03)
🟢	state_db.js	68.9 (0.98)	57.31 (1.06)	70.68 (1.59)	68.9 (0.98)

[hrmhatef]

Please rebase with the branch 38_refactor_for_OOP because there are some conflicts and it will help you for my comment.

[github-actions]

Commit SHA:3c0f8f0dca756f3a2e8628793e6a8bfb703376f4

Test coverage results 🧪

Code coverage diff between base branch:main and head branch: 54_checkpoint_interface 

Status	File	% Stmts	% Branch	% Funcs	% Lines
🟢	total	74.11 (0.78)	59.06 (1.13)	78.72 (0.95)	73.96 (0.79)
🟢	database.js	76.03 (1.03)	57.14 (1.83)	80 (0.97)	76.03 (1.03)
🟢	state_db.js	68.9 (0.98)	57.31 (1.06)	70.68 (1.59)	68.9 (0.98)

[hrmhatef]

Great!