Feat(compiler-base-session): Add some method for 'Session'.

[zong-zhe]

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

• N
• Y

issue #115

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

compiler-base-session

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
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

add constructor new_with_src_code() to 'Session' for constructing by source code.
add method 'emit_err()' to 'Session' for displaying error diagnostic.

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

• N
• Y

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

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

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 3272016812

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1107 unchanged lines in 8 files lost coverage.
• Overall coverage increased (+0.2%) to 59.675%

---

Files with Coverage Reduction	New Missed Lines	%
kclvm/3rdparty/rustc_span/src/source_map.rs	1	27.95%
kclvm/sema/src/resolver/schema.rs	2	80.99%
kclvm/sema/src/ty/mod.rs	35	66.02%
kclvm/3rdparty/rustc_span/src/analyze_source_file.rs	48	75.26%
kclvm/parser/src/lib.rs	54	83.69%
kclvm/sema/src/resolver/global.rs	294	61.42%
kclvm/sema/src/resolver/node.rs	298	69.25%
kclvm/3rdparty/rustc_span/src/lib.rs	375	33.75%

Totals
Change from base Build 3271916721:	0.2%
Covered Lines:	21875
Relevant Lines:	36657

---

💛 - Coveralls

[Peefy]

LGTM

[ldxdl]

LGTM