Add escaping of special characters in type names and properties

[cuminandpaprika]

Fixes an issue where type names such as "MyType:Here" would generate invalid sysl. This escapes the special characters in type names and endpoints

Changes proposed in this pull request:

• Adds escaping of typenames and endpoints

Checklist:

• [x] Added related tests
• [x] Made corresponding changes to the documentation

[codecov[bot]]

Codecov Report

Merging #896 into master will increase coverage by 0.02%. The diff coverage is 95.65%.

@@            Coverage Diff             @@
##           master     #896      +/-   ##
==========================================
+ Coverage   83.35%   83.38%   +0.02%     
==========================================
  Files          73       73              
  Lines       10609    10621      +12     
==========================================
+ Hits         8843     8856      +13     
  Misses       1432     1432              
+ Partials      334      333       -1     

Impacted Files	Coverage Δ
pkg/mod/gomod.go	73.68% <66.66%> (+1.27%)	:arrow_up:
pkg/importer/openapi.go	89.44% <100.00%> (ø)
...g/mermaid/integrationdiagram/integrationdiagram.go	86.66% <100.00%> (+2.29%)	:arrow_up:
pkg/mod/module.go	67.56% <100.00%> (+1.85%)	:arrow_up: