Migrator crashes if unexpected directories exist under config directory

[sameersubudhi]

What was the problem?

This PR resolves #175

How was it solved?

• Add null checks for conditional checks when migrating user config
• Default log level to info when migrating the user config, when getLogLevel errors out
• Determine the network based on the v3 networkIdentifier instead of blindly reading the directory name

How was it tested?

Locally

[codecov]

Codecov Report

Merging #180 (c836ba1) into release/2.0.0 (3cbb8a1) will decrease coverage by 0.48%.
Report is 3 commits behind head on release/2.0.0.
The diff coverage is 82.35%.

@@                Coverage Diff                @@
##           release/2.0.0     #180      +/-   ##
=================================================
- Coverage          86.42%   85.95%   -0.48%     
=================================================
  Files                 19       19              
  Lines                582      591       +9     
  Branches              81       82       +1     
=================================================
+ Hits                 503      508       +5     
- Misses                79       83       +4     

Files	Coverage Δ
src/utils/config.ts	88.46% <82.35%> (-2.45%)	⬇️

... and 1 file with indirect coverage changes

[nagdahimanshu]

LGTM 👍