Add commands to validate qlpack.yml and YAML MaD definitions

[jeongsoolee09]

qlt pack validate syntax; qlt pack validate version

Deps:

dotnet add package YamlDotNet --version 13.7.0
dotnet add package Semver --version 2.3.0

Sketch of the hypothetical usage scenarios:

$ qlt pack validate version --yml src/qlpack.yml test/qlpack.yml ext/qlpack.yml
Checking if the versions match up across the qlpack definitions.
src/qlpack.yml (advanced-security/javascript-sap-ui5-queries) is declared to be v0.3.0.
src/qlpack.yml (advanced-security/javascript-sap-ui5-queries) depends on advanced-security/javascript-sap-ui5-models: [{lb}, {ub}]
src/qlpack.yml (advanced-security/javascript-sap-ui5-queries) depends on advanced-security/javascript-sap-ui5-models: [{lb}, {ub}]
...
ext/qlpack.yml
...
{No contradictions.|{file1}, {file2}, {file3} does not match on pack {dep-pack-name}.}

$ qlt pack validate syntax --ext ext/ui5-extensions.yml
PASS: [some, row, "that's", correct]
FAIL: [some, row, "that's", wrong]
...
Done scanning.
========================================
Here are the rows that needs fixup:
2:4:32: [some, row, "that's", wrong]
17:4:32: [some, row, "that's", wrong]
...

[jeongsoolee09]

Closing due to branch being stale.