[build] UIExportModule cache contains full path

[tylersmalley]

In the produced build I am seeing absolute paths part of the cache within the modules of create_ui_exports_module.

From the nightly 8.0 snapshot, in built_assets/.cache/ui_bundles/babel/d3958a76611b949f634173c31b8feaa3.json

./d3958a76611b949f634173c31b8feaa3.json:{"remainingRequest":"node_modules/thread-loader/dist/cjs.js??ref--8-1!node_modules/babel-loader/lib/index.js??ref--8-2!src/optimize/create_ui_exports_module.js?{\"type\":\"hacks\",\"modules\":[\"plugins/xpack_main/hacks/check_xpack_info_change\",\"plugins/telemetry/hacks/telemetry_init\",\"plugins/telemetry/hacks/telemetry_opt_in\",\"plugins/graph/hacks/toggle_app_link_in_nav\",\"plugins/monitoring/hacks/toggle_app_link_in_nav\",\"plugins/security/hacks/on_session_timeout\",\"plugins/security/hacks/on_unauthorized_response\",\"plugins/searchprofiler/register\",\"plugins/ml/hacks/toggle_app_link_in_nav\",\"plugins/grokdebugger/sections/grokdebugger/register\",\"plugins/apm/hacks/toggle_app_link_in_nav\",\"plugins/code/hacks/toggle_app_link_in_nav\",\"plugins/canvas/lib/window_error_handler.js\",\"plugins/advanced_ui_actions/np_ready/public/legacy\",\"plugins/console/hacks/register\",\"plugins/dashboard_embeddable_container/initialize\",\"plugins/kibana/dev_tools/hacks/hide_empty_tools\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/region_map/public/legacy\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/tile_map/public/legacy\",\"plugins/timelion/hacks/toggle_app_link_in_nav\",\"plugins/timelion/lib/panel_registry\",\"plugins/timelion/panels/timechart/timechart\",\"plugins/ui_metric/hacks/ui_metric_init\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/vis_type_markdown/public/legacy\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/vis_type_metric/public/legacy\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/vis_type_table/public/legacy\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/vis_type_tagcloud/public/legacy\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/vis_type_timeseries/public/legacy\",\"/var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/vis_type_vega/public/legacy\",\"plugins/reporting/hacks/job_completion_notifier\"]}","dependencies":[{"path":"src/optimize/create_ui_exports_module.js","mtime":1568159874144},{"path":"node_modules/val-loader/dist/cjs.js","mtime":1568150927066},{"path":"node_modules/cache-loader/dist/cjs.js","mtime":1568150922712},{"path":"node_modules/thread-loader/dist/cjs.js","mtime":1568150926854},{"path":"node_modules/babel-loader/lib/index.js","mtime":1568150911897}],"contextDependencies":[],"result":[{"type":"Buffer","data":"base64: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"},null]}

There, you can see the full path to the Jenkins job: /var/lib/jenkins/workspace/elastic+kibana+pull-request/JOB/x-pack-ciGroup1/node/linux-immutable/kibana/build/kibana/src/legacy/core_plugins/region_map/public/legacy

[elasticmachine]

Pinging @elastic/kibana-operations

[tylersmalley]

@mistic mind taking a look when you return - this doesn't appear to be urgent.

[spalger]

I think this has to do with the fact that the uiExport is absolute... We should probably outlaw that somehow...