Issue #107: Make metrics and dimensions routes filterable by tags

config/ci_test.yaml.example

config/config.yaml.example

config/market_dimensions.yaml.example

config/market_metrics.yaml.example

config/market_tags.yaml.example

specs/blendb-api-v1.raml

src/api/controllers/engine.spec.ts

src/api/controllers/engine.ts

src/api/router-v1.ts

src/common/tag.ts

src/core/dimension.ts

src/core/engine.ts

src/core/metric.ts

src/util/configParser.spec.ts

src/util/configParser.ts

test/files/data.csv

test/files/data.ssv

test/files/data.tsv

test/files/metrics.csv