Change plugin install strategy to global install

[xuchaoying]

• Please check if the PR fulfills these requirements

• The commit message follows our guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

feature

• What is the related issue? (Use #issue_id to relate an open issue)

#147 #150

• Does this PR introduce a breaking change?

no

• Other information:

[codecov]

Codecov Report

Merging #152 into master will increase coverage by 0.09%.
The diff coverage is 97.32%.

@@            Coverage Diff             @@
##           master     #152      +/-   ##
==========================================
+ Coverage   92.37%   92.47%   +0.09%     
==========================================
  Files          45       48       +3     
  Lines        1614     1687      +73     
==========================================
+ Hits         1491     1560      +69     
- Misses        123      127       +4

Impacted Files	Coverage Δ
packages/svrx/lib/util/helper.js	100% <ø> (ø)	⬆️
...ges/svrx-util/lib/package-manager/tasks/install.js	85.71% <100%> (ø)
packages/svrx/lib/router/route.js	100% <100%> (ø)	⬆️
...ckages/svrx-util/lib/package-manager/tasks/view.js	100% <100%> (ø)
packages/svrx/lib/plugin/system.js	90.82% <100%> (-0.25%)	⬇️
packages/svrx/lib/plugin/loader.js	100% <100%> (+2.43%)	⬆️
packages/svrx-util/lib/npm/index.js	96.66% <100%> (+0.11%)	⬆️
packages/svrx-util/lib/name-formatter.js	100% <100%> (ø)
packages/svrx-util/lib/package-manager/index.js	100% <100%> (ø)
...util/lib/package-manager/plugin-package-manager.js	100% <100%> (ø)
... and 8 more

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