Feat(Compiler-Base): Add diagnostic handler.

[zong-zhe]

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• [ ] N
• [x] Y

issue #115

2. What is the scope of this PR (e.g. component or file name):

add diagnostic handler in compiler_base/error/lib.rs.

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• [ ] Affects user behaviors
• [ ] Contains syntax changes
• [ ] Contains variable changes
• [x] Contains experimental features
• [ ] Performance regression: Consumes more CPU
• [ ] Performance regression: Consumes more Memory
• [ ] Other

Turn TemplateLoader completely into a private crate for DiagnosticHandler. Move some comments from TemplateLoader to DiagnosticHandler. Move MessageArgs form 'compiler_base/error/diagnostic_message.rs' to 'compiler_base/error/lib.rs'. Add DiagnosticHandler in 'compiler_base/error/lib.rs'.

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• [x] N
• [ ] Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• [x] Unit test
• [ ] Integration test
• [ ] Benchmark (add benchmark stats below)
• [ ] Manual test (add detailed scripts or steps below)
• [ ] Other

test cases in 'compiler_base/error/tests.rs'.

6. Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[coveralls]

Pull Request Test Coverage Report for Build 2968688349

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 340 unchanged lines in 3 files lost coverage.
• Overall coverage increased (+0.3%) to 60.42%

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Files with Coverage Reduction	New Missed Lines	%
kclvm/tools/src/printer/tests.rs	1	95.24%
kclvm/runtime/src/api/kclvm.rs	25	44.44%
kclvm/runtime/src/value/api.rs	314	0%
<!--	Total:	340

Totals
Change from base Build 2949877482:	0.3%
Covered Lines:	23789
Relevant Lines:	39373

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💛 - Coveralls

[Peefy]

Two important things:

1. DiagnosticHandler preferably has a default method, which loads the default template
2. It is necessary to write clearly how to write *.ftl template in the lib.rs and new_with_template_dir methods, you can link the *.ftl official documentation.