feat!: remove default build dir overrides

[dpogue]

Platforms affected

iOS

Motivation and Context

Specifying CONFIGURATION_BUILD_DIR can cause issues with Cocoapods.

Closes #617 Closes #659 Closes #671

Description

Once upon a time, Xcode's default directory values had issues when there were spaces in project names, so we override the CONFIGURATION_BUILD_DIR and SHARED_PRECOMPS_DIR variables with our own paths.

However, this can interfere with Cocoapods, and Xcode should be able to handle things sensibly nowadays.

Unfortunately, that results in our build artifacts living somewhere in a randomly-named Xcode DerivedData directory, and then we can't do things like run the app in a simulator or on a device because we don't know the path to it. 🤦🏼‍♂️

Setting SYMROOT allows us to control the output directory of the built products, with the caveat that Xcode always creates a subdirectory named with the current configuration.

So instead of build/emulator, we'll have build/Debug-iphonesimulator and instead of build/device, we'll have build/Release-iphoneos.
Hypothetically this is better because now we are sure that debug and release files never get mixed up in the same output directory.

The downside is that this is a breaking change because it alters the path for the output .ipa files.

Testing

• [x] Unit tests pass
• [x] Created test project with spaces in the project name and confirmed that it builds successfully
• [x] Created a test project with Cocoapods that previously failed and confirmed that it builds successfully
• [x] Run a test project in the simulator (debug configuration)
• [x] Run a test project in the simulator (release configuration)
• [x] Run a test project on a device (debug configuration)
• [x] Run a test project on a device (release configuration)

Checklist

• [x] I've run the tests to see all new and existing tests pass
• [x] I added automated test coverage as appropriate for this change
• [x] If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)

[codecov-commenter]

Codecov Report

Merging #1310 (91dbae5) into master (3d6c71a) will increase coverage by 0.00%. The diff coverage is 64.70%.

@@           Coverage Diff           @@
##           master    #1310   +/-   ##
=======================================
  Coverage   78.48%   78.49%           
=======================================
  Files          15       15           
  Lines        1780     1790   +10     
=======================================
+ Hits         1397     1405    +8     
- Misses        383      385    +2     

Impacted Files	Coverage Δ
lib/run.js	21.73% <0.00%> (-0.24%)	:arrow_down:
lib/build.js	68.04% <84.61%> (+1.01%)	:arrow_up:

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