Package Manager should support creation of a lock file

[isc-jlechtne]

resolves #961

[isc-jlechtne]

Test coverage notes:

Modules required for testing:

1. Module with 0 dependencies
   • Module A
2. Module with 2 direct dependencies (they themselves don't have deps)
   • Module C
3. Module with dependency that has transient dependencies
   • Module D
4. Module with 1 dep (with transient), 1 dep (without transient)
   • Module F

Module A (0 deps)
- 0 dependencies
Module B (0 deps)
- 0 dependencies
Module C (2 deps w/o transient)
- 2 dependencies: A & B
Module D (1 dep w/ 2 transient)
- 1 dependency: C
Module E (1 dep w/o transient)
- 1 dependency: A
Module F (1 dep w/ 1 transient, 1 dep w/o transient)
- 2 dependencies: E & B

Edge cases:

1. All repository types (for simplicity, can make all other tests be filesystem in the integration tests files)
   • Module G
2. Module with multiple versions (both can specify version and defaults to latest version)
   • Module H
3. zpm "ci" on a module with no lock file && creating a lock file for a module that didn't already have one
   • Module I
4. Try install on a lock file that lists dependencies out of order
   • Module J
5. 2 modules in lock file with the same dependency module
   • Module K

Module G. Includes dependencies for (to be created as well):
- Module remote
- Module oras
- Module http
- Module filesystem
- Module perforce
Module H
- v2: One dependency: Module E (transient A)
- v3: Adds dependency Module B
Module I
- Base equivalent to Module F, just deleted the lock file
Module J (1 dep w/ 2 transient)
- Equivalent to Module D
- Different lock file
- Module D's lock file: A->B->C
- Module J's lock file: A->C->B (C should fail with B not installed)
Module K
- 2 dependencies: C & E (both with A)

[isc-kiyer]

@isc-jlechtne my first round of comments is up! Will review the tests once the comments are addressed.

[isc-eneil]

@isc-jlechtne Left another round of comments!

A couple of suggestions that won't stop me from upvoting because they're about code readability rather than functioning:
- For maintainability and since they are not meaningful, I would not number these test method names
- For readability, I'd name the module parameters meaningfully as well

[isc-kiyer]

@isc-jlechtne looks good overall! Few comments